vitamin-d-2 and Metabolic-Syndrome

Vitamin D is obtained from cutaneous production when 7-dehydrocholesterol is converted to vitamin D(3) (cholecalciferol) by ultraviolet B radiation or by oral intake of vitamin D. Rickets appeared to have been conquered with vitamin D intake, and many health care professionals thought the major health problems resulting from vitamin D deficiency had been resolved. However, rickets can be considered the tip of the vitamin D deficiency iceberg. In fact, vitamin D deficiency remains common in children and adults. An individual's vitamin D status is best evaluated by measuring the circulating 25-hydroxyvitamin D (25(OH)D3) concentration. There is increasing agreement that the optimal circulating 25(OH)D3 level should be approximately 30 ng/mL or above. Using this definition, it has been estimated that approximately three-quarters of all adults have low levels. In utero and during childhood, vitamin D deficiency can cause growth retardation and skeletal deformities and may increase the risk of hip fracture later in life. Vitamin D deficiency in adults can exacerbate osteopenia and osteoporosis, cause osteomalacia and muscle weakness, and increase the risk of fracture. More recently, associations between low vitamin D status and increased risk for various non-skeletal morbidities have been recognized; whether all of these associations are causally related to low vitamin D status remains to be determined. The discovery that most tissues and cells in the body have vitamin D receptors and that several possess the enzymatic machinery to convert the 25-hydroxyvitamin D3, to the active form, 1,25-dihydroxyvitamin D3, has provided new insights into the function of this vitamin. Of great interest is its role in decreasing the risk of many chronic illnesses, including common cancers, autoimmune diseases, infectious diseases, and cardiovascular disease. In this review I consider the nature of vitamin D deficiency, discuss its role in skeletal and non-skeletal health, and suggest strategies for prevention and treatment.

Topics: Asthma; Biomarkers; Bone Density Conservation Agents; Bone Diseases, Metabolic; Cholecalciferol; Dietary Supplements; Ergocalciferols; Humans; Metabolic Syndrome; Nervous System Diseases; Parathyroid Hormone; Rickets; Risk Factors; Sunlight; Vitamin D; Vitamin D Deficiency

Vitamin D deficiency is a common problem worldwide. Several studies have shown an association between vitamin D deficiency and the increased risk of metabolic syndrome. No previous study has compared the efficacy and safety of ergocalciferol at 40,000 versus 20,000 IU/week in patients with metabolic syndrome.. To evaluate the efficacy of ergocalciferol supplementation on serum 25-hydroxyvitamin D [25(OH)D] concentrations and to examine safety parameters in metabolic syndrome patients.. Outpatient department of Phramongkutklao Hospital, Bangkok, Thailand.. A randomized, double-blinded, parallel study was conducted in metabolic syndrome patients with vitamin D deficiency [25(OH)D <20 ng/mL]. Ninety patients were randomly assigned into three groups of 30 patients each. Group 1 was given two capsules of placebo/week, group 2 was given ergocalciferol 20,000 IU/week, and group 3 was given ergocalciferol 40,000 IU/week for 8 weeks.. serum 25(OH)D concentrations, serum calcium, safety, and corrected QT (QTc) interval.. Of the 90 patients enrolled, 84 patients completed the study. At the end of the study, the mean serum 25(OH)D in groups 2 and 3 significantly increased from the baseline (15.1 and 14.3 to 26.8 and 30.0 ng/mL, respectively). The increase in serum 25(OH)D in groups 2 and 3 were comparable and significantly greater than that of the placebo group. The percentage number of patients achieving normal vitamin D levels in groups 1, 2 and 3 were 3.3, 33.3, and 60.0 %, respectively, which were significantly different between groups (p < 0.001). Adverse reactions in both ergocalciferol treatment groups were not different from the placebo group (p > 0.05). Serum calcium levels did not change within and between groups of treatment. No significant change in QTc was observed in any patient.. Both 20,000 and 40,000 IU/week of ergocalciferol supplementation for 8 weeks were able to increase serum 25(OH)D concentrations significantly. However, more patients in the ergocalciferol 40,000 IU/week treatment group achieved a normal serum 25(OH)D level than in the group which received 20,000 IU/week. Clinicians would have informed of choosing the dosing regimen of ergocalciferol in metabolic syndrome patients.

Topics: 25-Hydroxyvitamin D 2; Aged; Arrhythmias, Cardiac; Calcifediol; Calcium; Dietary Supplements; Double-Blind Method; Ergocalciferols; Female; Humans; Hypercalcemia; Incidence; Male; Metabolic Syndrome; Middle Aged; Thailand; Time Factors; Vitamin D Deficiency

Vitamin D deficiency has been linked to many of the characteristics of metabolic syndrome, but whether supplementation with vitamin D2 would improve insulin sensitivity or metabolic risk factors is not known.. To investigate effects of vitamin D2 supplementation on insulin sensitivity and metabolic parameters in metabolic syndrome patients.. An 8-week, prospective randomized, double-blind, double-dummy, parallel trial was conducted in patients with metabolic syndrome. Ninety patients were equally randomized to receive vitamin D2 40,000 IU per week, vitamin D2 20,000 IU per week, or placebo. Outcomes were assessed at baseline and at the end of the study.. At week 8, serum 25(OH)D concentrations were increased significantly in both vitamin D2 groups (i.e., 20,000 IU and 40,000 IU) when compared with placebo group (11.72 ng/ml vs 2.80 ng/ml; p<0.001 and 15.74 ng/ml vs 2.80 ng/ml; p<0.001, respectively). Serum 25(OH)D concentrations in both vitamin D2 treatment groups were also significantly different (p=0.04). Insulin sensitivity assessed by homeostasis model assessment of insulin resistance (HOMA-IR) at week 8 in the three groups was not significantly different (p=0.36).. Vitamin D2 20,000 IU per week and 40,000 IU per week given for 8 weeks, were able to increase serum 25(OH)D concentrations significantly more than placebo group. However, HOMA-IR was not significantly different in the three groups. Our results do not support a positive effect of vitamin D2 on metabolic risk factors.

Topics: Adult; Aged; Aged, 80 and over; Dietary Supplements; Double-Blind Method; Ergocalciferols; Female; Homeostasis; Humans; Insulin Resistance; Male; Metabolic Syndrome; Middle Aged; Models, Biological; Placebos; Vitamin D

Vitamin D compounds may have extraskeletal functions. Chronic kidney disease (CKD) offers an opportunity to investigate these actions, as vitamin D deficiency is prevalent in this population and actions of vitamin D such as those on the heart and glucose metabolism are highly relevant. However, recent randomized controlled trials have tempered enthusiasm. We appraise a trial by de Boer et al. that addresses effects of paricalcitol on glucose metabolism in CKD, and offer perspectives on future trials.

Topics: Ergocalciferols; Glucose; Humans; Metabolic Syndrome; Randomized Controlled Trials as Topic; Renal Insufficiency, Chronic