Research paper
Vitamin D, Insulin Secretion, Sensitivity, and Lipids
Study answer
What this study found
Vitamin D3 supplementation raised serum 25(OH)D and lowered PTH, but it did not improve insulin secretion, insulin sensitivity, or lipid profile versus placebo after 6 months. Mean serum 25(OH)D reached 142.7 nmol/L in the vitamin D group versus 42.9 nmol/L in placebo, with no statistically significant between-group differences in the metabolic outcomes. Compliance was high at 98% in the vitamin D group and 97% in placebo. No cases of hypercalcemia or kidney stones were observed.
- Study & population
- Randomized, double-blind, placebo-controlled trial nested in the population-based Tromsø Study in Norway.
- Intervention
- Vitamin D3 was given as 20,000 IU per capsule by mouth twice per week for 6 months, using a placebo-controlled double-blind design.
- Key limitation
- The intervention arm was small, with only 49 completers, and follow-up lasted just 6 months, limiting power to detect modest metabolic effects.
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Open PDFOriginal abstract
OBJECTIVE Vitamin D deficiency is associated with an unfavorable metabolic profile in observational studies. The intention was to compare insulin sensitivity (the primary end point) and secretion and lipids in subjects with low and high serum 25(OH)D…