Key facts
- A genetic variation in the vitamin D receptor gene may influence diabetes risk reduction from high-dose vitamin D.
- Prediabetic individuals with AC or CC variants in the ApaI gene had a 19% lower chance of developing diabetes.
- Participants with the AA variant in the ApaI gene showed no benefit from vitamin D supplementation.
- The study involved over 2,000 U.S. adults with prediabetes taking 4,000 units of vitamin D or a placebo.
- Prediabetes affects over two in five U.S. adults and often progresses silently.
New research published in JAMA Network Open suggests that a specific genetic variation in the vitamin D receptor gene, known as ApaI, may determine whether high-dose vitamin D supplementation can lower the risk of developing Type 2 diabetes in prediabetic individuals. The study, which built upon the D2d trial, involved over 2,000 U.S. adults with prediabetes who were randomized to receive either 4,000 units of vitamin D daily or a placebo for up to 3.5 years.
Analysis of participants' DNA revealed that those carrying the AC or CC variants of the ApaI gene experienced a 19 percent lower chance of developing diabetes over the study period. In contrast, the approximately 30 percent of participants with the AA variation saw no discernible benefit from the supplementation. Prediabetes, characterized by higher-than-normal blood sugar levels, affects more than two in five U.S. adults and often progresses without noticeable symptoms.
Researchers believe these findings could pave the way for a more personalized approach to diabetes prevention, potentially utilizing genetic testing to identify individuals most likely to benefit from higher vitamin D doses. Current general recommendations for vitamin D intake are 600 to 800 IU daily, with higher doses potentially needed for deficiency or targeted prevention trials, though excessive intake can be harmful. Natural sources of vitamin D include fatty fish, beef liver, mushrooms, and egg yolks.