Impact of 6-month vitamin D supplementation on insulin sensitivity and secretion

  • Lemieux P & al.
  • Eur J Endocrinol
  • 1 Jul 2019

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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Takeaway

  • High-dose vitamin D supplementation (5000 IU daily) for 6 months significantly improved peripheral insulin sensitivity and ß-cell function in individuals at high risk for diabetes or newly diagnosed type 2 diabetes (T2D).

Why this matters

  • Findings suggest that vitamin D supplementation may reduce metabolic deterioration in individuals at high risk for diabetes or newly diagnosed T2D.

Study design

  • Patients at a high risk of diabetes or with newly diagnosed T2D (n=96) were randomly assigned to receive either vitamin D3 5000 IU or placebo for 6 months.
  • Peripheral insulin sensitivity (M value using a 2-hour hyperinsulinemic-euglycemic clamp), indices of insulin sensitivity, insulin secretion, ß-cell function (disposition index: M value x insulinogenic index) and other measures were evaluated at baseline and 6 months.
  • Funding: Johnson & Johnson and others.

Key results

  • Treatment group vs placebo group had significantly higher vitamin D level at:
    • 3 months (122.9 vs 52.2 nmol/L; P<.001 and>
    • 6 months (127.6 vs 51.8 nmol/L; P<.001>
  • At 6 months, treatment group vs placebo group showed beneficial effects on:
    • M value (mean change, 0.92; 95% CI, 0.24-1.59 vs −0.03; 95% CI, −0.73 to 0.67; P=.009), and
    • disposition index (mean change, 267.0; 95% CI, −343.4 to 877.4 vs −55.5; 95% CI, −696.3 to 585.3; P=.039).
  • No differences were observed between the groups for changes in insulin sensitivity derived from fasting values or the oral glucose tolerance test(OGTT), anthropometric measures, blood pressure, fasting glucose, 2-hour glucose post-OGTT, and HbA1c.
  • Few patients reported side effects such as gastrointestinal complaints, dizziness, anxiety, and hypoglycaemia.

Limitations

  • Single-centre study.
  • Only Caucasians were included restricting generalisability to other ethnic groups.