calcitriol and Anemia

Both, anemia and vitamin D deficiency are prevalent in patients with heart failure. According to recent evidence, vitamin D may stimulate erythropoiesis. We measured circulating 25-hydroxyvitamin D (25[OH]D), 1,25-dihydroxyvitamin D (1,25[OH](2)D) and hemoglobin (Hb) in a cross-sectional study in 364 end-stage heart failure patients awaiting cardiac transplantation, of whom 52.6% met the criteria for anemia (Hb < 13 g/dl in males and <12 g/dl in females). None of the patients were on erythrocyte-stimulating agents. Of the study cohort, 87.8% had 25(OH)D concentrations below 50 nmol/l. The mean Hb concentrations were significantly reduced in the lower tertiles of 25(OH)D and 1,25(OH)(2)D (P < 0.001). In multivariate-adjusted logistic regression analyses, the odds ratios for anemia of the lowest tertile of 25(OH)D (<18 nmol/l) and 1,25(OH)(2)D (<40 pmol/l) were 2.69 (1.46-5.00) and 4.08 (2.18-7.62) compared with their respective highest tertile (>32 nmol/l and >70 pmol/l). Patients with severe dual deficiency of 25(OH)D and 1,25(OH)(2)D had an odds ratio for anemia of 9.87 (95% CI 3.59-27.1) compared with patients in the highest tertile for both vitamin D metabolites. Circulating 1,25(OH)(2)D was directly related to circulating 25(OH)D levels and kidney function (P < 0.001), and inversely associated with C-reactive protein (P = 0.020). Our data demonstrate that vitamin D deficiency is independently associated with low Hb values and anemia in end-stage heart failure. Circulating 1,25(OH)(2)D is a better predictor of anemia than circulating 25(OH)D. Prospective randomized studies with administration of vitamin D (metabolites) will have to clarify if the association of vitamin D deficiency with anemia is causal.

Topics: Adult; Aged; Anemia; C-Reactive Protein; Cross-Sectional Studies; Female; Heart Failure; Hemoglobins; Humans; Logistic Models; Male; Middle Aged; Multivariate Analysis; Severity of Illness Index; Vitamin D; Vitamin D Deficiency

Vitamin D has a number of pleiotropic effects in a variety of tissues, in addition to its well-known effects on mineral metabolism. To determine whether it has an effect on erythropoiesis, we studied the association of the components of the vitamin D axis with the prevalence and severity of anemia in chronic kidney disease. We measured the concentrations of 25-hydroxyvitamin D (25D), 1,25-dihydroxyvitamin D (1,25D), and hemoglobin in a cross-sectional study of 1661 subjects in SEEK, a multi-center cohort study of chronic kidney disease patients in the United States, of whom 41% met the criteria for anemia. The mean hemoglobin concentrations significantly decreased with decreasing tertiles of 25D and 1,25D. These linear trends remained significant after adjustment for age, gender, ethnicity, eGFR, diabetes, and parathyroid hormone. In similarly adjusted models, the lowest tertiles of 25D and 1,25D were independently associated with 2.8- and 2.0-fold increased prevalence of anemia compared with their respective highest tertiles. Patients with severe dual deficiency of 25D and 1,25D had a 5.4-fold prevalence of anemia compared with those replete in both. Our study shows that 25D and 1,25D deficiency are independently associated with decreased hemoglobin levels and anemia in chronic kidney disease. Whether this association is causal requires further study.

Topics: Anemia; Bone and Bones; Calcinosis; Cohort Studies; Cross-Sectional Studies; Diabetes Mellitus; Dihydroxycholecalciferols; Hemoglobins; Humans; Kidney Failure, Chronic; Parathyroid Hormone; Prevalence; Renal Insufficiency, Chronic; United States; Vitamin D; Vitamin D Deficiency

Over 23 months, zinc toxicosis was diagnosed in 35 baboons aged 5-12 months in one galvanized metal and concrete cage complex with conditions that led to excessive exposure to environmental zinc. Clinical signs included reduced pigmentation of hair, skin, and mucous membranes (whiteness), alopecia, dehydration, emaciation, cachexia, dermatitis, diarrhea and, in six cases, severe gangrenous dermatitis of extremities. The syndrome was characterized by pancytopenia, elevated zinc and low copper serum concentrations, low vitamin D and bone-specific alkaline phosphatase levels, and atypical myelomonocytic proliferation of bone marrow. This syndrome emphasizes the importance of proper husbandry and cage design and indicates the potential of infant baboons as a model to study the effects of excessive zinc on development. This is the first report describing the epidemiologic and clinical presentation of zinc toxicosis in infant baboons in captivity.

Topics: Alopecia; Analysis of Variance; Anemia; Animals; Bone and Bones; Copper; Dermatitis; Diarrhea; DNA-Binding Proteins; Environmental Exposure; Flow Cytometry; Housing, Animal; Karyotyping; Light; Monkey Diseases; Papio; PAX5 Transcription Factor; Pigmentation; Radiography; Radioimmunoassay; Syndrome; Transcription Factors; Vitamin D; Zinc