Effects of Vitamin D 3 Supplementation on Glycaemic Parameters and Insulin Sensitivity in Pre-diabetic Adults: A Prospective Controlled Interventional Study.
Shankavi Ganesan, V Vidvath, T A Vidya
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In 30 seconds
This prospective controlled interventional study assessed daily oral vitamin D3 alongside lifestyle advice in 90 pre-diabetic adults aged 18–65 years in Chennai, compared with lifestyle advice alone. After 3 months, the supplementation group had greater improvements in fasting and post-prandial glucose, HbA1c and insulin resistance than controls (P < 0.001). Glycaemic normalisation occurred in 40% of the vitamin D group versus 11% of controls (P = 0.002). Serum 25(OH)D also increased, and no serious adverse events were recorded. The findings suggest potential benefit as an adjunct to lifestyle measures, but do not establish effects beyond the study period.
Key findings
- Fasting glucose fell from 112.6 ± 8.4 to 102.4 ± 7.3 mg/dL in the vitamin D group; improvements exceeded those in controls (P < 0.001).
- HOMA-IR decreased from 4.38 ± 1.02 to 3.41 ± 0.89, with greater improvement than in controls (P < 0.001).
- Glycaemic normalisation occurred in 40% of the vitamin D group versus 11% of controls (P = 0.002).
- Serum 25(OH)D rose from 18.4 ± 4.5 to 27.6 ± 2.8 ng/mL (P < 0.001); no serious adverse events were recorded.
Why it matters
Pre-diabetes is a stage at which improving glycaemic measures and insulin sensitivity may be clinically relevant. This study reports better short-term metabolic outcomes when vitamin D3 was added to lifestyle advice, including a higher proportion with glycaemic normalisation. These results add interventional evidence from an Indian pre-diabetic population, while the study’s limited duration means longer-term outcomes remain uncertain.
What to keep in mind
Follow-up was limited to 3 months, so durability of the reported changes is unknown.