Vitamin D deficiency has been associated with increased diabetes risk. But, the few published small trials of vitamin D supplementation haven’t shown a benefit on insulin function, which is important in blood sugar control. Included in this list is a new trial in the American Journal of Clinical Nutrition.
The trial used gold-standard methods to see if vitamin D supplements (a large dose at the study start followed by 4,000 IU daily) for 16 weeks would improve insulin function in 54 adults (average age, 32) who had low blood levels of vitamin D. The people were at increased risk of insulin resistance based on excess weight but were otherwise healthy.
“We found no effect of vitamin D supplementation on insulin resistance or secretion in overweight or obese people, compared to placebo,” says Barbora de Courten, MD, PhD, senior author of the study at Monash University in Australia. “So, we cannot recommend vitamin D supplements for primary prevention of type 2 diabetes.”
To learn more: The American Journal of Clinical Nutrition, June 2017