Association between Serum Vitamin D Metabolites and Metabolic Function in Healthy Asian Adults.
The association between low vitamin D status and the development of type 2 diabetes mellitus is well established; however, intervention trials that increased serum vitamin D (through ultraviolet B exposure or dietary supplementation) provide mixed outcomes. Recent evidence suggests that metabolites directly related to vitamin D receptor activation-1α,25-dihydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3-may be better markers of vitamin D repletion status. We tested the hypothesis that a vitamin D metabolite (VDM) index, calculated as the sum of normalized fasting serum concentrations of 1α,25-dihydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3, is associated with metabolic function. We measured subcutaneous and visceral adipose tissue volume, intrahepatic triglyceride content, maximum oxygen uptake, insulin sensitivity (4 h hyperinsulinemic-euglycemic clamp), and insulin secretion (3 h meal tolerance test with mathematical modeling) and calculated the VDM index in 65 healthy Asian adults. Subjects with a low VDM index had lower peripheral insulin sensitivity and beta-cell function compared to subjects with a high VDM index (both p < 0.05), matched for age, sex, BMI, and serum 25-hydroxyvitamin D3. Serum 25-hydroxyvitamin D3 was not associated with peripheral insulin sensitivity or beta-cell function. Our results suggest that, rather than enhancing vitamin D substrate availability, upregulation of vitamin D action is more likely to lead to improvements in glucose homeostasis.
['Ding|Cherlyn|C|0000-0002-5255-8677', 'Chan|Zhiling|Z|', 'Chooi|Yu Chung|YC|', 'Choo|John|J|', 'Sadananthan|Suresh Anand|SA|0000-0001-5938-1694', 'Michael|Navin|N|', 'Velan|Sambasivam Sendhil|SS|0000-0002-4096-0722', 'Leow|Melvin Khee-Shing|MK|0000-0002-2837-5889', 'Magkos|Faidon|F|0000-0002-1312-7364']
D000328:Adult D000368:Aged D044466:Asians D002112:Calcifediol D003924:Diabetes Mellitus, Type 2 D005260:Female D005947:Glucose D006706:Homeostasis D006801:Humans D007333:Insulin Resistance D000078790:Insulin Secretion D050152:Intra-Abdominal Fat D008297:Male D008875:Middle Aged D010100:Oxygen D010101:Oxygen Consumption D014280:Triglycerides D014807:Vitamin D D014808:Vitamin D Deficiency
vitamin D metabolites glucose homeostasis metabolic dysfunction