vitamin-b-12 and Hypothyroidism

Numerous studies have found an association between vitamin deficiency and thyroid disorders (TD). The presence of anti-parietal cell antibodies is indicative of reduced ability to absorb vitamin B12. Thus, this study reviewed the existing studies with the objective of assessing differences in the serum levels of vitamin B12 among patients with and without TD, the frequency of vitamin B12 deficiency in patients with TD, and the presence of anti-parietal cell antibodies in patients with TD.. A meta-analysis of random-effects model was conducted to calculate pooled frequencies, mean differences (MD), and their respective 95% confidence intervals (CI). We identified 64 studies that met our inclusion criteria (n = 28597).. We found that patients with hypothyroidism had lower vitamin B12 levels than healthy participants (MD: -60.67 pg/mL; 95% CI: -107.31 to -14.03 pg/mL; p = 0.01). No significant differences in vitamin B12 levels were observed between healthy participants and patients with hyperthyroidism (p = 0.78), autoimmune thyroid disease (AITD) (p = 0.22), or subclinical hypothyroidism (SH) (p = 0.79). The frequencies of vitamin B12 deficiency among patients with hypothyroidism, hyperthyroidism, SH, and AITD were 27%, 6%, 27%, and 18%, respectively.. Patients with hypothyroidism had lower levels of vitamin B12 than healthy participants. No significant differences were observed between vitamin B12 levels and hyperthyroidism, AITD, or SH.. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=324422, identifier (CRD42022324422).

Topics: Autoantibodies; Hashimoto Disease; Humans; Hyperthyroidism; Hypothyroidism; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Adult; Aged; Alcoholism; Anemia, Macrocytic; Female; Folic Acid; Folic Acid Deficiency; Humans; Hydroxocobalamin; Hypothyroidism; Infant, Newborn; Liver Failure; Male; Pregnancy; Risk Factors; Time Factors; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Alcoholism; Anemia, Hemolytic; Anticonvulsants; Bone Marrow Cells; Bone Marrow Diseases; Cells; Deoxyuridine; Erythrocytes, Abnormal; Female; Fluorouracil; Folic Acid; Folic Acid Deficiency; Formyltetrahydrofolates; Homocysteine; Humans; Hypothyroidism; Lymphocyte Activation; Methionine; Pregnancy; Pregnancy Complications; Statistics as Topic; Tetrahydrofolates; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Anemia, Pernicious; Animals; Antibodies; Autoantibodies; Gastric Juice; Humans; Hypothyroidism; Intrinsic Factor; Vitamin B 12

To assess the prevalence and determinants of haematinic deficiency (lack of B12 folate or iron) and macrocytosis in blood from a national population-based study of middle-aged and older adults.. A cross-sectional study involving 1,207 adults aged ≥45 years, recruited from a sub-study of the Irish National Survey of Lifestyle Attitudes and Nutrition (SLÁN 2007). Participants completed a health and lifestyle questionnaire and a standard food frequency questionnaire. Non-fasting blood samples were obtained for measurement of full blood count and expert morphological assessment, serum ferritin, soluble transferrin receptor assay (sTfR), B12, folate and coeliac antibodies. Blood samples were also assayed for thyroid function (T4, TSH), liver function, aminotransferase (AST) and gamma-glutamyl transferase (GGT).. The overall prevalence (95% C.I.) of anaemia (Hb <13.5 g/dl men and 11.3 g/dl women) was 4.6% (2.9%-6.4%) in men and 1.0% (0.2%-1.9%) in women. Iron deficiency (ferritin <17 ng/ml men and <11 ng/ml in women) was detected in 6.3% of participants (3.7% in males and 8.7% in females, p<0.001). Based on both low ferritin and raised sTfR (>21 nmol/ml) only 2.3% were iron-deficient. 3.0% and 2.7% were found to have low levels of serum folate (<2.3 ng/ml) and serum B12 (<120 ng/l) respectively. Clinically significant macrocytosis (MCV>99fl) was detected in 8.4% of subjects. Strong, significant and independent associations with macrocytosis were observed for lower social status, current smoking status, moderate to heavy alcohol intake, elevated GGT levels, deficiency of folate and vitamin B12, hypothyroidism and coeliac disease. The population attributable fraction (PAF) for macrocytosis associated with elevated GGT (25.0%) and smoking (24.6%) was higher than for excess alcohol intake (6.3%), folate deficiency (10.5%) or vitamin B12 (3.4%).. Haematinic deficiency and macrocytosis are common in middle-aged/older adults in Ireland. Macrocytosis is more likely to be attributable to an elevated GGT and smoking than vitamin B12 or folate deficiency.

Topics: Adult; Aged; Celiac Disease; Female; Folic Acid; Folic Acid Deficiency; gamma-Glutamyltransferase; Hematologic Diseases; Humans; Hypothyroidism; Ireland; Iron; Iron Deficiencies; Male; Middle Aged; Receptors, Transferrin; Smoking; Thyrotropin; Transaminases; Vitamin B 12; Vitamin B 12 Deficiency

Hypothyroidism may result in accelerated atherosclerosis. Hyperhomocysteinaemia is an independent risk factor for premature atherosclerotic vascular disease. The aim of the present study was to assess plasma total homocysteine (tHcy), folate and cobalamin concentrations in hypothyroid patients before and after treatment. Thirty-one hypothyroid and thirty health young women were studied. The hypothyroid patients were investigated in the untreated state and again after restoration of euthyroidism. The levels of homocysteine, folate, cobalamin and thyroid stimulating hormone (TSH), free thyroxine (fT(4)), free triiodothyronine (fT(3)) and renal function were measured before and after treatment. In hypothyroidism tHcy was higher but not statistically significant than in control group. Serum level of folate was higher and serum cobalamin was lower in the hypothyroid state. Following L-thyroxine therapy tHcy significantly decreased as well as the concentration of cobalamin. Level of folate remained unchanged. Univariate analysis in hypothyroid group indicated that tHcy negative correlated with creatinine clearance, fT(3), fT(4), cobalamin and positive with TSH. In multivariate analysis tHcy correlated with creatinine clearance, cobalamin and fT(4). Thyroid status influences the plasma tHcy. Free triiodothyronine and next free thyroxine have the greatest negative influence. This would account for hyperhomocysteinemia in the hypothyroid state and premature atherogenesis.

Topics: Adult; Creatine; Female; Folic Acid; Homocysteine; Humans; Hypothyroidism; Middle Aged; Thyrotropin; Thyroxine; Vitamin B 12

Prevalence of vitamin B12 deficiency is occasionally found to be coexisting in patients with hypothyroidism causing persistence of symptoms concomitant to both diseases even on adequate thyroxine supplementation.. A single-centric non-interventional cross sectional study was carried over a period of 1 year. 100 hypothyroid patients were evaluated for prevalence of anemia, and investigated for the etiology. Serum Vitamin B12 was obtained and an association was studied between Vitamin B12 and anti TPO and anti Thyroglobulin antibodies. Here, vitamin B12 deficiency was defined as <160 pg/mL.. Among 100 hypothyroid patients, 31% were males and 69% were females. The mean age of patients was 36.09±12.864 years. 68% patients were found to be Vitamin B12 deficient, and 73.5% of this deficient population were females. 78.6% patients with raised Anti TPO antibodies had vitamin B12 deficiency (p-value = 0.01), while 78% patients with raised Anti Thyroglobulin antibodies were vitamin B12 deficient (p-value = 0.07). The Pearson correlation coefficient (r) was -0.302 (p = 0.002) and -0.253 (p = 0.011) between Vitamin B12 anti anti TPO and anti Thyroglobulin antibodies respectively, thus showing a negative correlation between both.. Thyroid hormones affect erythropoiesis, thus causing anemia in a deficient condition. In iodine sufficient areas, most common cause of hypothyroidism is autoimmune, predisposing individuals to other autoimmune diseases, one being pernicious anemia. In the studied anemic hypothyroid population, Vitamin B12 deficiency was found correlated with raised levels of serum anti-TPO and anti-Thyroglobulin antibodies. Supplementation of B12 may alleviate hypothyroid symptoms, thus making itself a novel addition in the routine hypothyroid prescription. References Aon M, Taha S, Mahfouz K, et al. Vitamin B12 (cobalamin) deficiency in overt and subclinical primary hypothyroidism. Clin Med Insights Endocrinol Diabetes 2022;15:11795514221086634. Ness-Abramof R, Nabriski DA, Shapiro MS, et al. Prevalence and evaluation of B12 deficiency in patients with autoimmune thyroid disease. Am J Med Sci;332(3):119-122.

Topics: Adult; Anemia; Cross-Sectional Studies; Female; Hospitals, Teaching; Humans; Hypothyroidism; Male; Middle Aged; Tertiary Healthcare; Vitamin B 12; Vitamin B 12 Deficiency; Young Adult

Anemia frequently occurs during course of clinical thyroid diseases. Without proper diagnosis & effective treatment of underlying thyroid disease, it is often difficult to achieve complete correction of anemia.. The present study was conducted to assess prevalence & types of anaemia in patients with thyroid disorders.. A cross sectional study was conducted on 160 patients including both hypothyroid & hyperthyroid patients at OPD/IPD in SRN Hospital affiliated to MLN Medical college Prayagraj between July 2021 & August 2022. Blood samples were taken to estimate CBC, GBP with Retic count, S. ferritin, S. folate, S. Vitamin B12, Thyroid profile. Data was entered in MS Excel Spreadsheet & appropriate statistical package applied.. Out of 144 hypothyroid patients, 102 (70.83%) were found to be anaemic & out of 16 hyperthyroid patients, 6 (37.5%) were found to be anaemic. In 102 anaemic hypothyroid patients, 56 (54.9%)had normocytic normochromic, 25 (24.5%) had microcytic and 21 (20.5%) had macrocytic anaemia. In 6 anaemic hyperthyroid patients, 3 (50%) had normocytic normochromic, 2(33.33%) had microcytic and 1 (16.67%) had macrocytic anaemia.. High prevalence of anaemia was found in patients with thyroid disorders. Anaemia is an uncommon finding in hyperthyroidism but when present may be similar to that present in hypothyroidism. The most common type of anaemia in both hyperthyroidism & hypothyroidism was found to be normocytic normochromic, followed by microcytic & least common being macrocytic. References Suhail N, Abu Alsel BT, Batool S. Prevalence and association of thyroid dysfunction with anemia/body iron status among northern border Saudi population. Int J Med Res Health Sci 2020;9(3):1-7. Peraka SA, Karre S, Ravuri S, et al., To evaluate prevalence of anemia in hypothyroid patients. J Diagn Pathol Oncol 2019;4(2):110-113.

Topics: Anemia; Anemia, Macrocytic; Cross-Sectional Studies; Ferritins; Folic Acid; Humans; Hyperthyroidism; Hypothyroidism; Thyroid Diseases; Thyroid Hormones; Vitamin B 12

Topics: Humans; Hypothyroidism; Prevalence; Vitamin B 12; Vitamin B 12 Deficiency

Diffuse hair loss (DHL) is a common problem in adult women and has a major impact on quality of life. Ascertaining the etiological diagnosis is a challenging task in such patients. Satisfactory treatment can only be instituted after ascertaining the cause of hair loss.. To study the clinico-epidemiological profile of nonscarring DHL in females and to ascertain its underlying etiological factors.. Of a total of 110 females, who presented with nonscarring DHL to the outpatient dermatology department, 100 qualified for inclusion in the study. A detailed history, clinical examination, and laboratory investigations were performed in all the patients. Statistical analysis was performed on the data collected.. Of 100 cases of DHL which were included in the study, commonest was chronic telogen effluvium (CTE) (62%), followed by female pattern hair loss (FPHL) (22%) and acute telogen effluvium (ATE) (16%). Incidence of hair loss was highest in 21-40 years age group. Psychological stress was seen to be a precipitating factor in 18 patients and found most commonly in women belong to CTE group (n-16, 25.8%). Hemoglobin levels ranged from 80 to 142 gm/L (mean: 119 ± 110). Low hemoglobin level (<120 gm/L) was observed in 57% patients. Total serum ferritin <10 ng/mL was seen in 20 patients, vitamin B12 < 211 pg/mL in 76 cases, vitamin D3 < 30 ng/mL in 81 cases. Subclinical hypothyroidism was present in 11% cases.. Nonscarring DHL is a multifactorial condition with highest incidence in 21- to 40-year age group. Serum ferritin, serum vitamin B12, and D3 levels seem to have a contributing role in the pathogenesis of hair loss, and their supplementation may be needed for a faster regrowth of hair in all cases of hair loss irrespective of the pattern.

Topics: Adolescent; Adult; Age Distribution; Alopecia Areata; Cholecalciferol; Female; Ferritins; Hemoglobins; Humans; Hypothyroidism; Incidence; India; Middle Aged; Prospective Studies; Stress, Psychological; Tertiary Care Centers; Vitamin B 12; Young Adult

Topics: Adult; Anemia, Iron-Deficiency; Anemia, Pernicious; Biomarkers; Female; Humans; Hypothyroidism; Pancytopenia; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Administration, Oral; Dose-Response Relationship, Drug; Female; Gastritis, Atrophic; Graves Disease; Helicobacter Infections; Helicobacter pylori; Hormone Replacement Therapy; Humans; Hypothyroidism; Intestinal Absorption; Iodine Radioisotopes; Middle Aged; Thyrotropin; Thyroxine; Vitamin B 12; Vitamin B 12 Deficiency

Autoimmune thyroiditis can be diagnosed by measuring patients' serum levels of thyroid stimulating hormone (TSH), anti-thyroglobulin antibody (TGA), and anti-thyroid microsomal antibody (TMA). This study evaluated whether there were hematinic deficiencies, high blood homocysteine levels, and serum gastric parietal cell antibody (GPCA) positivity in patients with TGA or TMA.. The blood hemoglobin (Hb), iron, vitamin B12, folic acid, homocysteine and TSH concentrations and the serum GPCA level in 190 TGA- or TMA-positive patients were measured and compared with the corresponding levels in 190 age- and sex-matched healthy control subjects.. We found that 31 (16.3%), 27 (14.2%), 12 (6.3%), and 2 (1.1%) TGA- or TMA-positive patients had deficiencies of Hb (Men<13g/dL, Women<12g/dL), iron (< 60μg/dL), vitamin B12 (< 200pg/mL), and folic acid (< 4ng/mL), respectively. Moreover, 25 (13.2%) and 48 (25.3%) TGA- or TMA-positive patients had abnormally high blood homocysteine level and serum GPCA positivity, respectively. TGA- or TMA-positive patients had a significantly higher frequency of Hb (p<0.001), iron (p<0.001), or vitamin B12 deficiency (p=0.001), of abnormally elevated blood homocysteine level (p=0.001), or of serum GPCA positivity (p<0.001) than healthy control subjects. Of 190 TGA- or TMA-positive patients, 8 (4.2%) had lower serum TSH level (< 0.1μIU/mL, suggestive of hyperthyroidism), 163 (85.8%) had serum TSH level within normal range (0.1-4.5μIU/mL), and 19 (10%) had higher serum TSH level (>4.5μIU/mL, suggestive of hypothyroidis).. There are significant deficiencies of hemoglobin, iron, and vitamin B12, abnormally high blood homocysteine levels, and serum GPCA positivity in TGA- or TMA-positive patients. In addition, the majority (85.8%) of TGA- or TMA-positive patients had euthyroid and only a small portion (14.2%) of TGA- or TMA-positive patients had either hypothyroidism or hyperthyroidism.

Topics: Adult; Aged; Aged, 80 and over; Autoantibodies; Biomarkers; Case-Control Studies; Female; Folic Acid; Folic Acid Deficiency; Hemoglobins; Homocysteine; Humans; Hyperthyroidism; Hypothyroidism; Iron; Iron Deficiencies; Male; Middle Aged; Parietal Cells, Gastric; Thyroiditis, Autoimmune; Vitamin B 12; Vitamin B 12 Deficiency

The cblE disorder is an inherited disorder of vitamin B12 metabolism that results in elevated levels of homocysteine and decreased methionine in body fluids. Renal complications have been reported in patients with cblC disease, but not in those with cblE disease. The renal complications of cblC disease include thrombotic microangiopathy (TMA), neonatal hemolytic uremic syndrome, chronic renal failure, tubulointerstitial nephritis and proximal renal tubular acidosis. Previously, we reported a patient with cblC disease who had an atypical glomerulopathy that manifested with proteinuria and progressive renal insufficiency.. Studies were done on cultured fibroblasts. Renal biopsy tissue was examined by light and electron microscopy. There was decreased incorporation of labeled methyltetrahydrofolate and decreased synthesis of methylcobalamin. Complementation analysis placed the patient into the cblE complementation group. The findings from the histological and ultrastructural studies of renal biopsy were similar, but not identical, to those of idiopathic membranoproliferative glomerulonephritis (MPGN) and overlapped with those of TMA.. We describe a patient with cblE disease who had an atypical glomerulopathy similar to MPGN. Additional findings included migraine headaches, hypothyroidism and livedo reticularis.

Topics: Anemia, Megaloblastic; Biopsy; Cells, Cultured; Disease Progression; Female; Fibroblasts; Genetic Complementation Test; Genetic Predisposition to Disease; Glomerulonephritis, Membranoproliferative; Homocystinuria; Humans; Hydroxocobalamin; Hypothyroidism; Kidney; Livedo Reticularis; Migraine Disorders; Phenotype; Predictive Value of Tests; Renal Insufficiency, Chronic; Time Factors; Vitamin B 12; Vitamin B Complex; Young Adult

Topics: Adult; Anus, Imperforate; Ectodermal Dysplasia; Growth Disorders; Hearing Loss, Sensorineural; Humans; Hypothyroidism; Intellectual Disability; Male; Nose; Pancreatic Diseases; Pancytopenia; Vitamin B 12; Vitamin B 12 Deficiency; Young Adult

Autoimmune thyroid disease (AITD) is frequently accompanied by other organ-specific diseases. We investigated the frequency of the association AITD-Biermer's disease (BD) in patients with AITD by investigating the prevalence of intrinsic factor antibodies (IF-Ab).. Sera from 113 patients with AITD (hypo- or hyperthyroidism) were screened for the presence of type I IF-Ab with a competitive automated immunoassay based. Matched sera from 113 patients with dysthyroidism (not AITD) were tested.. Four IF-Ab positive patients suffered from AITD. BD was known for two of them and strongly suspected in the two others. All patients with no AITD tested IF-Ab negative. B12 levels were often low whatever the etiology.. The prevalence of IF-AbI is higher (3.5%) in patients with AITD. Prospective studies should investigate whether correcting thyroid dysfunction improves vitamin B12 levels, and establish whether routine screening for gastric autoimmunity is clinically useful or purely academic.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anemia, Pernicious; Autoantibodies; Child; Child, Preschool; Humans; Hyperthyroidism; Hypothyroidism; Infant; Intrinsic Factor; Middle Aged; Prevalence; Thyroiditis, Autoimmune; Thyroxine; Triiodothyronine; Vitamin B 12; Young Adult

To assess the prevalence and clinical features of B12 deficiency in hypothyroid patients and to evaluate clinical response in symptoms to B12 replacement therapy.. One hundred and sixteen hypothyroid patients from our endocrine clinic were evaluated for signs and symptoms of vitamin B12 deficiency. Laboratory parameters including Haemoglobin (Hb), MCV, Vitamin B12 levels and presence of anti thyroid antibodies were analyzed. Patients with low B12 levels were treated with parenteral intramuscular vitamin B12 monthly, and monitored for improvement of symptoms.. A total of 116 patients (95 females and 21 males) were evaluated. Forty six (39.6%) hypothyroid patients had low vitamin B12 levels. Males and females had the same prevalence of B12 deficiency. Generalized weakness, impaired memory, depression, numbness and decreased reflexes were more frequently noted in B12 deficient patients, but failed to achieve statistical significance when compared with B12 sufficient patients. The mean Hb in B12 deficient group was 11.9 +/- 1.6 mg/dl and 12.4 +/- 1.7 mg/dl in the B12 sufficient group, however the mean MCV did not differ in the two groups. Patients with B12 deficiency did not have a higher prevalence of anaemia. Thyroid antibodies were checked in half the patients and 67% had positive titers for anti thyroid antibodies. Prevalence of vitamin B12 deficiency did not differ in patients with positive antibodies (43.2%) compared to those with negative antibodies (38.9%) (p= 0.759). Twenty four hypothyroid patients with B12 deficiency received intramuscular vitamin B12 injections monthly and improvement in symptoms was noted in 58.3% of these subjects. Additionally, 21 subjects complained of symptoms consistent with B12 deficiency but who had normal range B12, levels and were prescribed monthly B12 injections and 8 (40%) had good subjective clinical response at 6 months.. There is a high (approx 40%) prevalence of B12 deficiency in hypothyroid patients. Traditional symptoms are not a good guide to determining presence of B12 deficiency. Screening for vitamin B12 levels should be undertaken in all hypothyroid patients, irrespective of their thyroid antibody status. Replacement of B12 leads to improvement in symptoms, although a placebo effect cannot be excluded, as a number of patients without B12 deficiency also appeared to respond to B12, administration.

Topics: Adult; Aged; Aged, 80 and over; Female; Follow-Up Studies; Humans; Hypothyroidism; Injections, Intramuscular; Male; Middle Aged; Pakistan; Prevalence; Prognosis; Retrospective Studies; Vitamin B 12; Vitamin B 12 Deficiency; Vitamin B Complex

Generalized pruritus can often be the primary manifestation of systemic disease.. To determine how frequently generalized pruritus had a systemic etiology in an outpatient population seen in a dermatology department and whether any identifiable patient characteristics meant a systemic explanation of generalized pruritus was more likely.. A prospective controlled study of 55 patients with generalized pruritus and 41 healthy age- and sex-matched control subjects. Clinical data were collected from patients and laboratory parameters investigated in both patients and healthy control subjects to determine the frequency of systemic disease in each group.. Of 55 patients, 12 had a systemic cause of pruritus. Pruritus was the initial symptom of systemic disease in eight of these patients. The underlying diseases included hypothyroidism, chronic lymphocytic leukemia, hepatitis C, hepatitis B, diabetes mellitus, lung cancer, uremia, and iron deficiency anemia. Of these, iron deficiency anemia was the most common cause. Compared with the control group, mean serum hemoglobin, iron, and cyanocobalamin (vitamin B(12)) levels in patients with generalized pruritus were lower. No other patient characteristics were statistically associated with systemic causes of pruritus.. Generalized pruritus was the initial symptom of a systemic disease in 8 of 55 patients presenting to a dermatology outpatient clinic with this complaint. A number of underlying diseases were identified, of which the most common was iron deficiency anemia.

Topics: Adult; Aged; Aged, 80 and over; Anemia, Iron-Deficiency; Case-Control Studies; Diabetes Complications; Female; Hemoglobins; Hepatitis, Viral, Human; Humans; Hypothyroidism; Iron; Leukemia, Lymphocytic, Chronic, B-Cell; Lung Neoplasms; Male; Middle Aged; Prospective Studies; Prostatic Neoplasms; Pruritus; Statistics, Nonparametric; Uremia; Vitamin B 12

The aim of the present study was to evaluate plasma total homocysteine (Hcys) and serum fibrinogen concentrations in subclinical hypothyroid (SH) and overt hypothyroid patients before and after L-thyroxine (LT4) replacement and to compare them in euthyroid subjects. Fifteen SH and 20 hypothyroid premenopausal women were recruited in the study. We measured fasting plasma levels of Hcys and serum levels of free thyroxine (fT4), free triiodothyronine (fT3), thyrotropin (TSH), folate, vitamin B12, fibrinogen, renal functions, and lipid profiles in patients with SH and overt hypothyroid patients before and after LT4 treatment. Eleven healthy women were included in the study as a control group. Pretreatment Hcys levels were similar in SH and control subjects, whereas mean fibrinogen level of SH patients was higher than that of control subjects (p<0.05). Baseline Hcys (p<0.01) and fibrinogen (p<0.001) levels of the overt hypothyroid patients were significantly higher than those of the healthy subjects, and the pretreatment Hcys levels decreased with LT4 treatment (p<0.001). In conclusion, our data support that SH is not associated with hyperhomocysteinemia and Hcys does not appear to contribute to the increased risk for atherosclerotic disease in patients with SH.

Topics: Adult; Case-Control Studies; Female; Fibrinogen; Folic Acid; Homocysteine; Humans; Hypothyroidism; Kidney; Middle Aged; Thyrotropin; Thyroxine; Triiodothyronine; Vitamin B 12

Hyperhomocysteinemia is an independent risk factor for coronary, peripheral and cerebrovascular diseases. Moderately elevated total homocysteine (tHcy) levels have been reported in patients with overt hypothyroidism. Plasma tHcy concentration is affected by several physiological factors and is elevated under conditions of impaired folate and cobalamin status and in renal failure. The aim of this study was to assess plasma tHcy concentrations and to evaluate the role of potential determinants of plasma tHcy levels in hypothyroid patients. Fasting plasma tHcy, serum homocysteine-related vitamins folate and vitamin B(12), serum cystatin C (CysC) and creatinine, were determined in 22 hypothyroid patients and compared with 25 healthy control subjects. Creatinine clearance (CCr) was calculated using the Cockroft-Gault formula. Plasma tHcy levels were determined by HPLC with fluorescence detection and serum CysC by automated particle enhanced immunoturbidimetry. Plasma tHcy, creatinine levels were significantly higher, and serum CysC levels, and creatinine clearance values were lower in hypothyroid patients than in control subjects. Folate levels were lower in hypothyroidic group compared to the control group. There were no differences in vitamin B(12) levels between hypothyroid and control groups. Positive correlation was noted between tHcy and creatinine levels in hypothyroid patients (r = 0.596); however, an inverse correlation was found between tHcy and folate levels (r = -0.705) in hypothyroid patients. In conclusion, tHcy was increased in hypothyroidism, and this increase was more strongly associated with changes in serum folate than in serum creatinine and CysC, suggesting an altered folate status.

Topics: Adult; Aged; Chromatography, High Pressure Liquid; Creatinine; Cystatins; Data Interpretation, Statistical; Female; Folic Acid; Homocysteine; Humans; Hypothyroidism; Kidney; Male; Middle Aged; Nephelometry and Turbidimetry; Vitamin B 12

Clinical hypothyroidism is associated with hyperhomocysteinemia, whereas the opposite is seen in hyperthyroidism. The effects of mild thyroid dysfunction on homocysteine concentrations are not known. We performed the following study to investigate this. Total homocysteine, vitamins B6 and B12, folate, fibrinogen, plasminogen activator inhibitor type 1, and lipids were measured in 11 subjects at baseline and after methionine loading. Subjects began methimazole (MMI), 40 mg daily, and were restudied during 2 stages of hypothyroidism. Liothyronine was added and subjects were restudied once thyrotropin normalized. Methimazole was stopped and studies were repeated during 2 stages of hyperthyroidism. Data were analyzed using repeated-measures analysis of variance. Post-methionine homocysteine decreased in each hypothyroid study compared with baseline (28.8+/-10.7, 27.5+/-9.9 vs 34.4+/-9.2 micromol/L, respectively). In addition, both fasting and post-methionine homocysteine decreased in the euthyroid/MMI study arm compared with baseline despite equivalent thyrotropin values (fasting, 7.5+/-3.0 vs 8.8+/-3.5 micromol/L, P<.05; and post-methionine, 27.2+/-10.6 vs 34.4+/-9.2 micromol/L, P<.05, respectively). Fasting homocysteine decreased in the first hyperthyroidism study arm compared with baseline (6.6+/-2.3 vs 8.8+/-3.5 micromol/L, P<.05) and post-methionine homocysteine decreased in both hyperthyroid arms compared with baseline (25.2+/-8.1, 24.2+/-10 vs 34.4+/-9.2 micromol/L, P<.05 respectively). In conclusion, mild thyroid dysfunction changes homocysteine metabolism. Unexpectedly, our results suggest a homocysteine-lowering effect of MMI.

Topics: Adolescent; Adult; Female; Fibrinogen; Folic Acid; Homocysteine; Humans; Hypothyroidism; Lipids; Logistic Models; Male; Methimazole; Methionine; Plasminogen Activator Inhibitor 1; Thyrotropin; Vitamin B 12; Vitamin B 6

It is claimed in a limited number of studies carried out on human beings that plasma homocysteine levels increased in hypothyroid patients and decreased in hyperthyroid patients.. The aim of this study is to determine total plasma homocysteine, thyroid function tests, vitamin B12, folic acid and lipid levels and to explore the relations among them in rat models with induced hypothyroidism and hyperthyroidism with a view to investigating whether hypothyroid and hyperthyroid rat models could represent human hypothyroidism and hyperthyroidism models.. The study included 30 male Wistar Albino species rats with a mean weight of 200 - 250 g. Rats were randomly divided into 3 groups as 1) hypothyroid group, 2) hyperthyroid group and 3) control group. Hypothyroidism was induced by adding 10 mg/kg/day propylthiouracil to rats' drinking water for 30 days. In order to induce hyperthyroidism, rats were administered 10 microg/100 g L-thyroxin ampule via intraperitoneal route for 10 days.. We found that total plasma homocysteine level of the hypothyroid group was significantly lower than those of the control group (p<0.05) and the hyperthyroid group (p<0.001). Total plasma homocysteine level of the hypothyroid group was found insignificantly higher than that of the control group (p>0.05) and significantly higher than that of the hyperthyroid group (p<0.001). We established a significant and positive correlation between total plasma homocysteine level and thyroid hormone levels. We did not identify a significant relation between total plasma homocysteine level and serum folic acid and serum vitamin B12 levels.. Our findings are different from the findings reported in human hypothyroidism and hyperthyroidism studies. We believe that hypothyroid and hyperthyroid rat models cannot represent human hypothyroidism and hyperthyroidism models.

Topics: Animals; Antithyroid Agents; Cholesterol; Folic Acid; Homocysteine; Hyperthyroidism; Hypothyroidism; Lipids; Male; Propylthiouracil; Rats; Rats, Wistar; Thyroid Function Tests; Thyroxine; Vitamin B 12

The serum/plasma total homocysteine (tHcy) concentration, now recognized as an independent risk factor for accelerated atherosclerotic disease, is increased in overtly hypothyroid patients, and it decreases with thyroid replacement therapy. Whether or not individuals with subclinical hypothyroidism also increase their tHcy concentrations, and whether this elevation might help to explain the increased prevalence of the atherosclerotic diseases observed in this condition, remains unclear. If individuals with subclinical hypothyroidism have higher tHcy concentrations than euthyroid subjects, there would be added incentive to treat this condition earlier. In this cross-sectional study (New Mexico Elder Health Survey) of a randomly selected sample of Medicare recipients (age > or =65 years), no significant difference in serum tHcy concentrations could be detected between the 112 participants with subclinical hypothyroidism (Groups 2 and 3) and the 643 participants with thyrotropin (TSH) values < or =4.6 microU/mL (Group 1) after adjusting for differences in gender, ethnicity, age, and serum concentrations of folate, vitamin B(12), and creatinine. Only those participants with the highest TSH levels (>10 microU/mL) (Group 3) had a significantly higher prevalence of coronary heart disease (CHD) when compared against Group 1 participants (p = 0.007). No consistent significant differences in the prevalences of CHD or in the CHD risk factors examined were observed when all participants with subclinical hypothyroidism (Groups 2 and 3 combined) were compared against Group 1 participants.

Topics: Aged; Aged, 80 and over; Coronary Disease; Creatinine; Fasting; Female; Folic Acid; Health Surveys; Homocysteine; Humans; Hypothyroidism; Male; New Mexico; Prevalence; Risk Factors; Vitamin B 12

Hyperhomocysteinemia is a risk factor for premature atherosclerotic vascular disease and venous thrombosis. The aim of the present study was to assess plasma total homocysteine (tHCys) concentrations in adolescent patients with subclinical hypothyroidism.. Nineteen patients with subclinical hypothyroidism and 19 healthy children were studied. Fasting plasma concentrations of tHCys and its putative determinants (plasma concentrations of free thyroxine [FT4], folate, vitamin B12 and renal function) were measured.. tHCys concentrations showed no statistical difference between patients and controls (p > 0.05). Moreover, the difference in tHCys and total cholesterol concentrations was not significant between patients with mild TSH elevations (< or = 10 mIU/l) and patients with prominent TSH elevations (> 10 mIU/l). No correlation was found between tHCys concentrations and its putative determinants.. We concluded that plasma tHCys concentrations were not increased in adolescent patients with subclinical hypothyroidism.

Topics: Adolescent; Cholesterol; Fasting; Female; Folic Acid; Homocysteine; Humans; Hyperhomocysteinemia; Hypothyroidism; Isoantibodies; Kidney; Kidney Function Tests; Thyroiditis, Autoimmune; Thyrotropin; Thyroxine; Triiodothyronine; Vitamin B 12

Hyperhomocysteinaemia is a risk factor for premature atherosclerotic vascular disease and venous thrombosis. The aim of the present study was to assess plasma total homocysteine (tHCys) concentrations in hypo- as well as hyperthyroid patients before and after treatment, and to evaluate the role of potential determinants of plasma tHCys levels in these patients.. Prospective follow up study.. Fifty hypothyroid and 46 hyperthyroid patients were studied in the untreated state and again after restoration of euthyroidism.. Fasting plasma levels of tHCys and its putative determinants (plasma levels of free thyroxine (fT4), folate, vitamin B(12), renal function, sex, age, smoking status and the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene were measured before and after treatment.. Restoration of the euthyroid state decreased both tHCys (17.6 +/- 10.2-13.0 +/- 4.7 micromol/l; P < 0.005) and creatinine (83.9 +/- 22.0-69.8 +/- 14.2 micromol/l; P < 0.005) in hypothyroid patients and increased both tHCys (10.7 +/- 2.5-13.4 +/- 3.3 micromol/l; P < 0.005) and creatinine (49.0 +/- 15.4-66.5 +/- 15.0 micromol/l; P < 0.005) in hyperthyroid patients (values as mean +/- SD). Folate levels were lower in the hypothyroid group compared to the hyperthyroid group (11.7 +/- 6.4 and 15.1 +/- 7.6 nmol/l; P < 0.05). Pretreatment tHCys levels correlated with log fT(4) (r = - 0.47), folate (r = - 0.21), plasma creatinine (r = 0.45) and age (r = 0.35) but not with C677T genotype. Multivariate analysis indicated that pretreatment log(fT(4)) levels and age accounted for 28% the variability of pre-treatment tHCys (tHCys = 14.2-5.50 log(fT(4)) + 0.14 age). After treatment the logarithm of the change (Delta) in fT(4) (expressed as the post-treatment fT(4)/pre-treatment fT(4) ratio) accounted for 45% of the variability in change of tHCys ( tHCys = - 0.07-4.94 log ( fT(4))); there was no independent contribution of changes in creatinine which was, however, strongly related to changes in tHCys (r = 0.61).. Plasma tHCys concentrations increased in hypothyroidism and decreased in hyperthyroidism. Plasma fT(4) is an independent determinant of tHCys concentrations. Lower folate levels and a lower creatinine clearance in hypo-thyroidism, and a higher creatinine clearance in hyperthyroidism only partially explain the changes in tHCys.

Topics: Adult; Age Factors; Aged; Analysis of Variance; Biomarkers; Cardiovascular Diseases; Creatinine; Female; Folic Acid; Follow-Up Studies; Homocysteine; Humans; Hyperthyroidism; Hypothyroidism; Linear Models; Male; Metabolic Clearance Rate; Methylenetetrahydrofolate Dehydrogenase (NADP); Middle Aged; Polymorphism, Genetic; Prospective Studies; Risk Factors; Sex Factors; Smoking; Thyroid Function Tests; Thyroxine; Vitamin B 12

Topics: Folic Acid; Homocysteine; Humans; Hyperthyroidism; Hypothyroidism; Transcobalamins; Vitamin B 12

To determine the prevalence of pernicious anaemia in patients with Type 1 diabetes mellitus and autoimmune thyroid disease.. A randomly selected asymptomatic group of 63 patients with Type 1 diabetes who also had autoimmune thyroid disease was studied. Blood samples were taken and assayed for serum B12. Those subjects with serum B12 concentrations below the reference range had a further blood sample taken for determination of intrinsic factor antibody.. One patient had been diagnosed previously to have pernicious anaemia. Three patients had low serum B12 concentration and positive intrinsic factor antibody, confirming the diagnosis of pernicious anaemia. The prevalence of pernicious anaemia in this population with Type 1 diabetes and concomitant autoimmune thyroid disease was 6.3%. In female patients the prevalence of pernicious anaemia was 8.5%.. Patients who have both Type 1 diabetes mellitus and autoimmune thyroid disease are at risk of developing pernicious anaemia.

Topics: Aged; Aged, 80 and over; Anemia, Pernicious; Autoantibodies; Diabetes Mellitus, Type 1; Female; Folic Acid; Graves Disease; Humans; Hypothyroidism; Intrinsic Factor; Middle Aged; Prevalence; Vitamin B 12

If all the elements of the complete blood cell count are considered in clinical context, they can provide an invaluable guide to the possible causes of a patient's anemia and the tests needed for definitive diagnosis. Unnecessary tests not only add to the expense of treatment but may result in delayed diagnosis and inappropriate treatment in some cases.

Topics: Aged; Algorithms; Anemia, Macrocytic; Blood Cell Count; Blood Transfusion; Diagnosis, Differential; Female; Ferrous Compounds; Humans; Hypothyroidism; Pancytopenia; Thyroid Function Tests; Vitamin B 12; Vitamin B 12 Deficiency

We found a higher plasma concentration of total homocysteine (tHcy), an independent risk factor for cardiovascular disease, in patients with hypothyroidism (mean, 16.3 micromol/L; 95% confidence interval [CI], 14.7 to 17.9 micromol/L) than in healthy controls (mean, 10.5 micromol/L; 95% CI, 10.1 to 10.9 micromol/L). The tHcy level of hyperthyroid patients did not differ significantly from that of the controls. Serum creatinine was higher in hypothyroid patients and lower in hyperthyroid patients than in controls, whereas serum folate was higher in hyperthyroid patients compared with the two other groups. In multivariate analysis, these differences did not explain the higher tHcy concentration in hypothyroidism. We confirmed the observation of elevated serum cholesterol in hypothyroidism, which together with the hyperhomocysteinemia may contribute to an accelerated atherogenesis in these patients.

Topics: Adult; Aged; Arteriosclerosis; Cardiovascular Diseases; Cholesterol; Creatinine; Female; Folic Acid; Homocysteine; Humans; Hyperthyroidism; Hypothyroidism; Male; Middle Aged; Multivariate Analysis; Risk Factors; Thyroxine; Triiodothyronine; Vitamin B 12

To determine the prevalence of latent pernicious anaemia (PA) in Type 1 diabetics.. Patients with Type 1 diabetes were screened at two yearly intervals on a continuing basis.. Diabetic Unit, Royal Perth Hospital, Western Australia.. Three hundred and seventy-one patients, 156 females and 215 males, attending a diabetic clinic. They were classified as having Type 1 diabetes on the basis of age of onset less than 40 years and requiring insulin from the start.. Serum cobalamin levels were measured and studies of thyroid function and a blood count were done. Patients with a reduced serum level of cobalamin had tests for cobalamin absorption.. Six patients had a low serum cobalamin level; five showed malabsorption of the vitamin which could be corrected by the addition of intrinsic factor. Four of these patients had no clinical signs of PA. The fifth was mildly anaemic (haemoglobin level 111 g/L) and had megaloblastic bone marrow. He was classified as having frank PA. The sixth patient was not available for further testing. These results give a prevalence of latent PA of 11 per 1000 in Type 1 diabetics, compared with 3.9 per 1000 in diabetics with clinically manifest disease and 1.27 per 1000 in the general population. All four patients with latent PA had hypothyroidism, based on low thyroxine levels, increased levels of thyroid stimulating hormone and the presence of thyroid antibodies.. Latent PA is not uncommon in Type 1 diabetics. It has a long preclinical course and occurs in those patients with thyroid disease. The screening of Type 1 diabetics for latent PA has worthwhile benefits as a "preventive" health measure.

Topics: Anemia, Pernicious; Diabetes Mellitus, Type 1; Female; Follow-Up Studies; Humans; Hypothyroidism; Male; Mass Screening; Thyroid Function Tests; Vitamin B 12

Intestinal absorption of vitamin B12 as measured by the Schillin test was studied in 50 patients with primary hypothyroidism of autoimmune origin. The impaired absorption of vitamin B12 was found in 24% of the patients studied, and in 6% a clinically evident form of pernicious anemia was diagnosed. The patients with hypothyroidism and simultaneous defect in absorption of vitamin B12 were characterized by more frequent occurrence of the high titer of antithyroid microsomal antibodies, higher blood serum concentration of TSH and lower blood content of hemoglobin as compared with hypothyroid patients having normal intestinal absorption of vitamin B12.

Topics: Adult; Aged; Anemia, Pernicious; Autoimmune Diseases; Female; Humans; Hypothyroidism; Intestinal Absorption; Male; Middle Aged; Vitamin B 12

The effect of hypo- and hyperthyroidism on vitamin B-12 metabolism in the rat was studied by measuring methylmalonic acid excretion, B-12 content of liver and oxidation of 2-[14C]histidine. Ten percent pectin was added to increase severity of B-12 deficiency. The addition of thiouracil to a diet containing 10% pectin decreased the excretion of methylmalonic acid suggesting an amelioration of the B-12 deficiency. It was found that part of this decreased methylmalonic acid excretion was due to a decreased food consumption with a correspondingly decreased intake of branched-chain amino acids which are precursors of methylmalonic acid. When attempts were made to increase the protein intake of animals receiving thiouracil so their amino acid intake was equal to that of the control animals, methylmalonic acid excretion was still lower than that of the controls. It was also found that the vitamin B-12 content of the liver was higher in the animals receiving thiouracil than in the controls. Thyroidectomy had the same effect as feeding thiouracil. Liver B-12 levels are rapidly depleted on a B-12 deficient diet containing 10% pectin. It appears that hypothyroidism, induced either by thyroidectomy or by feeding thiouracil, slows the rate of depletion of hepatic B-12 which in turn facilitates the metabolism of methylmalonic acid and decreases its excretion in the urine.

Topics: Animals; Dietary Proteins; Folic Acid; Histidine; Hypothyroidism; Liver; Malonates; Methylmalonic Acid; Mice; Rats; Thiouracil; Thyroid Hormones; Thyroidectomy; Vitamin B 12; Vitamin B 12 Deficiency

A patient with pernicious anemia who developed a mild macrocytic anemia after many years of monthly vitamin B(12) therapy is presented. There was no response to the addition of folic acid and multivitamins. Evaluation for causes of elevated mean corpuscular volume and consideration of associated autoimmune disorders led to the diagnosis of primary hypothyroidism. Treatment with levothyroxine led to correction of the hematologic abnormalities over a four-month period. The anemia of hypothyroidism may present with macrocytic indices and this diagnosis should be suspected when this finding is noted.

Topics: Aged; Anemia, Macrocytic; Female; Folic Acid; Humans; Hypothyroidism; Vitamin B 12

In an unselected series of 202 patients with hypothyroidism anaemia was present on diagnosis in 39 of 172 women and 14 of 30 men. Microcytic anaemia was present in only nine patients in the entire series. The average of the mean corpuscular volume (MCV) of all the patients was 90 fl. Fifty-three of 118 patients who were studied in detail had normal serum concentrations of vitamin B12, folic acid and iron. The haemoglobin was low in 13 of these 53 patients and rose on treatment with thyroxine alone. The MCV exceeded 90 fl in 29 of these 53 patients and in three it was greater than 100 fl. The MCV invariably fell on treatment with thyroxine even if the initial value was within the normal range. Nine of this group of 53 patients had both anaemia and an increased MCV--the macrocytic anaemia of hypothyroidism. A minor degree of anisocytosis of the red blood cells, which was reduced by treatment with thyroxine, was also demonstrated. Acanthocytes were present in the blood films of 32 out of 172 patients but in only five did the abnormal cells comprise more than 0-5 per cent of the red cell population. The incidence of new cases of pernicious anaemia diagnosed concurrently with the hypothyroidism in the carefully studied group of 118 patients was 8-5 per cent. The MCV of hypothyroid patients with low levels of vitamin B12 was often no greater than in patients with uncomplicated hypothyroidism. The MCV is not therefore a useful discriminant in the diagnosis of pernicious anaemia in hypothyroidism. The serum iron concentration was less than 12 mumol/1 in 60 out of 118 patients. The total iron binding capacity of the serum was increased in only 21 of these 60 patients. In 42 hypothyroid patients the low serum iron concentration was not associated with low levels of either vitamin B12 or folate and of these patients 22 were anaemic. Despite the very low percentage saturation of the iron binding capacity in all of these patients with a low serum iron, a lack of iron did not seem to be the usual determinant of anaemia when it occurred.

Topics: Acanthocytes; Adolescent; Adult; Aged; Anemia; Anemia, Pernicious; Erythrocyte Count; Female; Folic Acid; Hemoglobins; Humans; Hypothyroidism; Iron; Male; Middle Aged; Vitamin B 12

We measured the levels of serum folate and vitamin B12 in newly discovered hypothyroid (n =56) and hyperthyroid (n =47) patients and in age- and sex-matched control subjects (n =103). Except for one patient with latent pernicious anemia, serum folate and vitamin B12 levels did not differ greatly in our patients and in our control subjects. Another patient was receiving monthly injections of cyanocobalamin for previously diagnosed pernicious anemia. We conclude that abnormalities of thyroid function per se did not alter serum folate or vitamin B12 levels in our patients.

Topics: Adult; Aged; Anemia, Pernicious; Female; Folic Acid; Humans; Hyperthyroidism; Hypothyroidism; Male; Middle Aged; Vitamin B 12

Qualitative and quantitative studies of erythropoiesis in 23 patients with hypothyroidism and 21 patients with hyperthryoidism included routine hematologic evaluation, bone marrow morphology, status of serum iron, B12 and folate red blood cell mass and plasma volume by radioisotope methods, erythrokinetics and radiobioassay of plasma erythropoietin. A majority of patients with the hypothyroid state had significant reduction in red blood cell mas per kg of body weight. The presence of anemia in many of these patients was not evident from hemoglobin and hematocrit values due to concomitant reduction of plasma volume. The erythrokinetic data in hypothyroid patients provided evidence of significant decline of the erythropoietic activity of the bone marrow. Erythroid cells in the marrow were depleted and also showed reduced proliferative activity as indicated by lower 3H-thymidine labeling index. Plasma erythropoietin levels were reduced, often being immeasurable by the polycythemic mouse bioassay technique. These changes in erythropoiesis in the hypothyroid state appear to be a part of physiological adjustment to the reduced oxygen requirement of the tissues due to diminished basal metabolic rate. Similar investigations revealed mild erythrocytosis in a significant proportion of patients with hyperthyroidism. Failure of erythrocytosis to occur in other patients of this group was associated with impaired erythropoiesis due to a deficiency of hemopoietic nutrients such as iron, vitamin B12 and folate. The mean plasma erythropoietin level of these patients was significantly elevated; in 4 patients the levels were in the upper normal range whereas in the rest, the values were above the normal range. The bone marrow showed erythyroid hyperplasia in all patients with hyperthyroidism. The mean 3H-thymidine labeling index of the erythroblasts was also significantly higher than normal in hyperthyroidism; in 8 patients the index was within the normal range whereas in the remaining 13 it was above the normal range. Erythrokinetic studies also provided evidences of increased erythropoietic activity in the bone marrow. It is postulated that thyroid hormones stimulate erythropoiesis, sometimes leading to erythrocytosis provided there is no deficiency of hemopoietic nutrients. Stimulation of erythropoiesis by thryoid hormones appears to be mediated through erythropoietin.

Topics: Biological Assay; Bone Marrow Examination; Cell Division; Erythrocytes; Erythropoiesis; Erythropoietin; Folic Acid; Hematocrit; Hemoglobinometry; Humans; Hyperthyroidism; Hypothyroidism; Iron; Isoenzymes; L-Lactate Dehydrogenase; Plasma Volume; Polycythemia; Thymidine; Vitamin B 12

Evidence of cell-mediated immunity to gastric intrinsic factor was present in 86% of patients with pernicious anaemia and in at least 13% of patients with hyperthyroidism, 21% of patients with atrophic gastritis, and four out of nine (46%) patients with hypogammaglobulinaemia. Controls gave negative results. The four patients with hypogammaglobulinaemia and cell-mediated immunity to intrinsic factor had evidence of impaired gastric function.

Topics: Agammaglobulinemia; Anemia, Pernicious; Antibodies; Autoimmune Diseases; Cell Migration Inhibition; Diabetes Mellitus; Female; Gastritis; Hematocrit; Humans; Hyperthyroidism; Hypothyroidism; Immunity, Cellular; Intestinal Absorption; Intrinsic Factor; Leukocytes; Lymphocyte Activation; Male; Vitamin B 12

Topics: Adult; Aged; Alcoholism; Anemia, Macrocytic; Anemia, Pernicious; Blood Cell Count; Bone Marrow Cells; Erythroplasia; Female; Folic Acid; Folic Acid Deficiency; Hematopoietic Stem Cells; Humans; Hypothyroidism; Kidney Diseases; L-Lactate Dehydrogenase; Male; Neutrophils; Nutrition Disorders; Pregnancy; Pregnancy Complications, Hematologic; Reticulocytes; Vitamin B 12

Topics: Aged; Cervical Vertebrae; Dementia; Depression; Female; Gastrectomy; Home Care Services; Humans; Hypothyroidism; Spinal Diseases; Thyroxine; Vitamin B 12

Topics: Animals; Hyperthyroidism; Hypothyroidism; Leukocytes; Methylthiouracil; Peritonitis; Phagocytosis; Rabbits; Thyroid Hormones; Vitamin B 12

Topics: Adult; Aged; Arteriosclerosis; Ascorbic Acid; Calcium; Cholesterol; Coronary Disease; Electrocardiography; Female; Gluconates; Humans; Hypothyroidism; Male; Middle Aged; Niacinamide; Pantothenic Acid; Riboflavin; Thiamine; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones; Thyroxine; Vitamin B 12

Topics: Adult; Aged; Anemia, Hypochromic; Anemia, Macrocytic; Anemia, Pernicious; Bone Marrow Examination; Cestode Infections; Erythrocytes; Female; Hematocrit; Hemoglobinometry; Humans; Hyperthyroidism; Hypothyroidism; Iron; Kidney Failure, Chronic; Leukocyte Count; Male; Middle Aged; Neoplasms; Pregnancy; Transferases; Vitamin B 12

Topics: Adult; Aged; Anemia; Anemia, Macrocytic; Anemia, Pernicious; Biopsy; Blood Cell Count; Bone Marrow Examination; Carotenoids; Cholesterol; Diagnosis, Differential; Female; Folic Acid; Folic Acid Deficiency; Gastric Acidity Determination; Hematocrit; Hemoglobinometry; Humans; Hypothyroidism; Iron; Jejunum; Kidney Function Tests; Liver Function Tests; Middle Aged; Myxedema; Thyroid Function Tests; Thyroidectomy; Vitamin B 12

Topics: Adult; Aged; Angiography; Electrocardiography; Electrophoresis; Female; Humans; Hypothyroidism; Isoenzymes; L-Lactate Dehydrogenase; Male; Middle Aged; Myxedema; Vitamin B 12

Topics: Addison Disease; Adrenal Insufficiency; Anemia, Pernicious; Autoimmune Diseases; Cortisone; Diabetes Mellitus; Diagnosis; Drug Therapy; Fludrocortisone; Humans; Hypoadrenocorticism, Familial; Hypothyroidism; Thyroxine; Vitamin B 12; Vitiligo

Topics: Anemia; Anemia, Hypochromic; Anemia, Macrocytic; Anemia, Pernicious; Humans; Hypothyroidism; Iron; Myxedema; Thyroid Hormones; Vitamin B 12

Topics: Cerebral Palsy; Child; Clinical Laboratory Techniques; Down Syndrome; Electrocardiography; Electrophysiology; Humans; Hyperthyroidism; Hypothyroidism; Infant; Infant, Newborn; Meningitis; Physiology; Reflex; Reflex, Abnormal; Triiodothyronine; Vitamin B 12

Topics: Absorption; Blood Volume Determination; Diagnosis; Female; Humans; Hyperthyroidism; Hypothyroidism; Iodine Isotopes; Kidney Function Tests; Phosphorus Isotopes; Placenta; Pregnancy; Radioisotopes; Radiotherapy; Serum Albumin; Serum Albumin, Radio-Iodinated; Thyroid Function Tests; Vitamin B 12

Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Humans; Hypothyroidism; Postgastrectomy Syndromes; Protein Deficiency; Thyroid Hormones; Vitamin B 12

Topics: Hematinics; Humans; Hypothyroidism; Vitamin B 12; Vitamin B 12 Deficiency; Vitamin B Complex

Topics: Diabetes Mellitus; Female; Fetus; Folic Acid; Hematinics; Humans; Hypothyroidism; Liver Diseases; Metabolic Diseases; Pregnancy; Vitamin B 12; Vitamin B Complex; Vitamins

Topics: Humans; Hypothyroidism; Muscle Contraction; Muscles; Vitamin B 12; Vitamin B Complex

Topics: Anemia; Hyperthyroidism; Hypothyroidism; Vitamin B 12