4X reduction in prediabetes progressing to T2D if more than 50 ng of vitamin D – RCT
Vitamin D and Risk for Type 2 Diabetes in People With Prediabetes : A Systematic Review and Meta-analysis of Individual Participant Data From 3 Randomized Clinical Trials
Ann Intern Med. 2023 Mar;176(3):355-363. doi: 10.7326/M22-3018 PDF is behind a paywall
Anastassios G Pittas 1, Tetsuya Kawahara 2, Rolf Jorde 3, Bess Dawson-Hughes 4, Ellen M Vickery 1, Edith Angellotti 5, Jason Nelson 1, Thomas A Trikalinos 6, Ethan M Balk 6
Background: The role of vitamin D in people who are at risk for type 2 diabetes remains unclear.
Purpose: To evaluate whether administration of vitamin D decreases risk for diabetes among people with prediabetes.
Data sources: PubMed, Embase, and ClinicalTrials.gov from database inception through 9 December 2022.
Study selection: Eligible trials that were specifically designed and conducted to test the effects of oral vitamin D versus placebo on new-onset diabetes in adults with prediabetes.
Data extraction: The primary outcome was time to event for new-onset diabetes. Secondary outcomes were regression to normal glucose regulation and adverse events. Prespecified analyses (both unadjusted and adjusted for key baseline variables) were conducted according to the intention-to-treat principle.
Data synthesis: Three randomized trials were included, which tested cholecalciferol, 20 000 IU (500 mcg) weekly; cholecalciferol, 4000 IU (100 mcg) daily; or eldecalcitol, 0.75 mcg daily, versus matching placebos. Trials were at low risk of bias.
Vitamin D reduced risk for diabetes by 15% (hazard ratio, 0.85 [95% CI, 0.75 to 0.96]) in adjusted analyses, with a 3-year absolute risk reduction of 3.3% (CI, 0.6% to 6.0%). The effect of vitamin D did not differ in prespecified subgroups.
Among participants assigned to the vitamin D group who maintained an intratrial mean serum 25-hydroxyvitamin D level of at least 125 nmol/L (≥50 ng/mL) compared with 50 to 74 nmol/L (20 to 29 ng/mL) during follow-up, cholecalciferol reduced risk for diabetes by 76% (hazard ratio, 0.24 [CI, 0.16 to 0.36]), with a 3-year absolute risk reduction of 18.1% (CI, 11.7% to 24.6%).
Vitamin D increased the likelihood of regression to normal glucose regulation by 30% (rate ratio, 1.30 [CI, 1.16 to 1.46]).
There was no evidence of difference in the rate ratios for adverse events
(kidney stones: 1.17 [CI, 0.69 to 1.99];
hypercalcemia: 2.34 [CI, 0.83 to 6.66];
hypercalciuria: 1.65 [CI, 0.83 to 3.28];
death: 0.85 [CI, 0.31 to 2.36]).
Limitations: Studies of people with prediabetes do not apply to the general population. Trials may not have been powered for safety outcomes.
Conclusion: In adults with prediabetes, vitamin D was effective in decreasing risk for diabetes.
Primary funding source: None. (PROSPERO: CRD42020163522).
VitaminDWiki – Overview Diabetes and vitamin D contains
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Diabetic Epidemic
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VitaminDWiki – Diabetes category contains
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