Effect of Vitamin D and/or Calcium Supplementation on Pancreatic β-Cell Function in Subjects with Prediabetes: A Randomized, Controlled Trial
Dongdong Zhang, Xiaoqin Zhong, Cheng Cheng, Zhiwei Su, Yuan Xue, Yaping Liu, Yujing Zhang, Mingming Feng, Ze Xu, Tong Zhao, Luoya Zhang, Haoyue Huang, Wenjie Li, Xing Li
Abstract
So far, the potential role of vitamin D in β-cell function remains a matter of debate. Therefore, a randomized, placebo-controlled trial (RCT) was conducted to evaluate the effect of a vitamin D supplement with or without calcium on β-cell function in a Chinese population with prediabetes. Two hundred and forty-three subjects were randomly assigned in a 2-by-2 factorial-design RCT to receive either 1600 IU/day vitamin D3 with/or 500 mg/day calcium for 24 weeks. The results showed that oral administration of vitamin D and calcium could increase the secretion of insulin. Vitamin D-insufficient individuals displayed an increment in the disposition index (adjusted change = 0.31, 95%CI: 0.07, 0.56) after treatment by vitamin D + calcium. It illustrated that supplementation with vitamin D and calcium might improve the function of pancreatic β-cell in prediabetes with low serum 25(OH)D levels. However, further studies are needed to confirm the findings. Given the low vitamin D content in natural foods, it is necessary to fortify processed foods with vitamin D.