Data from a 6-year study suggest that those with serum 25-hydroxyvitamin D levels ≥60 nmol/L have a 3.5-fold lower risk for developing type 1 diabetes vs. those with lower levels.
“Previous studies proposed the existence of an association between vitamin D deficiency and risk of type 1 diabetes, but this is the first time that the theory has been tested in a way that provides the dose-response relationship,” Cedric Garland, DrPH, FACE, professor in the department of family and preventive medicine at the University of California at San Diego, said in a press release.
Using blood samples from military service members collected through the Department of Defense Serum Registry for disease surveillance, Garland and colleagues analyzed 1,000 samples from healthy members who later developed type 1 diabetes. Each case was individually matched with a healthy control based on blood draw date, age, length of service and sex. The median elapsed time between serum collection and first diagnosis of diabetes was 1 year, according to the abstract.
Researchers compared serum levels of 25-(OH)D to determine the optimal level needed to lower the risk for type 1 diabetes.
According to data, the ORs for insulin-requiring diabetes by quintile of serum 25-(OH)D were 3.5 (95% CI, 2.0-6.0); 2.5 (95% CI, 1.5-4.2); 0.8 (95% CI, 0.4-1.4); 1.1 (95% CI, 0.6-2.8); and 1.0 (reference; P<.001).
Based on serum 25-(OH)D, the quintiles were <43 nmol/L (median 28 nmol/L); 43 nmol/L to 59 nmol/L (median 52 nmol/L); 60 nmol/L to 77 nmol/L (median 70 nmol/L); 78 nmol/L to 99 nmol/L (median 88 nmol/L) and ≥100 nmol/L (median 128 nmol/L).
According to the press release, Garland estimates that the level of 25-(OH)D needed to prevent half of the cases of type 1 diabetes is 50 ng/mL, based on these and other data.
“While there are a few conditions that influence vitamin D metabolism, for most people, 4,000 IU per day of vitamin D3 will be needed to achieve the effective levels,” Garland said. “This beneficial effect is present at these intakes only for vitamin D3. Reliance should not be placed on different forms of vitamin D and mega doses should be avoided, as most of the benefits for prevention of disease are for doses less than 10,000 IU per day.”
Disclosure: The study was supported by a congressional allocation to the Diabetes Research Institute of the University of Miami through the Naval Health Research Center in San Diego.
Source: Endocrine Today.