Vitamin D supplementation reduces C‐reactive protein and insulin resistance in women with type 2 diabetes mellitus

Abstract

A randomized, double blind, placebo‐controlled clinical trial was conducted to evaluate the effect of vitamin D supplementation on C‐reactive protein (CRP) and insulin resistance in 104 postmenopausal women with type 2 diabetes mellitus. Participants received a vitamin D capsule –cholecalciferol 4,000 IU‐ (n=52) or placebo (n=52), daily during 6 mo. The study was approved by the Ethics committee at NIPH. All participants signed an informed consent.ResultsMedian CRP concentration was 5.0 mg/L (ir: 1.0, 8.5). HOMA index at baseline was 7.13 ± 3.8. Serum 25‐OH‐D at baseline was 54.5 ± 15.7 nmol/L. 93% of patients had 25‐OH‐D levels <80 nmol/L, and 40% <50 nmol/L. Experimental groups were similar on most variables at baseline. After 6 months, there was an increase in serum 25‐OH‐D of 25 ± 2.6 nmol/L in the supplemented group, and an increase of 0.8 ± 2.2 nmol/L in the placebo group (p<0.001). There was a 64% reduction on CRP among supplemented women who had baseline CRP concentrations >5.0 mg/L (p<0.05). A 24% reduction in HOMA‐IR after 6 months was observed among supplemented women who had a baseline HOMA >6.0 (p=0.06).ConclusionVitamin D supplementation during 6 months reduced CRP levels and insulin resistance among diabetic, postmenopausal women with high HOMA index and elevated CRP levels.Supported by Ellison Medical/INF, Boston.