People with low blood levels of vitamin D are at increased risk for developing type 2 diabetes, even if they aren’t overweight, according to researchers at the University of Malaga in Spain. Vitamin D levels and body mass index (BMI) were assessed in almost 150 people, who also were tested for diabetes, prediabetes, or other blood sugar metabolic disorders. Obese people who didn’t have diabetes or related disorders had higher vitamin D levels than those with diabetes. Lean people with diabetes or related disorders were more likely to have low vitamin D levels compared to those without such disorders. It is unclear whether vitamin D played a role in causing diabetes or was merely associated with the disease. The researchers conclude that, “…vitamin D is associated more closely with glucose metabolism than is obesity.”
The concern that vitamin D can be toxic is over. “The evidence is clear that vitamin D toxicity is one of the rarest medical conditions and is typically due to intentional or inadvertent intake of extremely high doses,” states Dr. Michael Holick in an editorial accompanying a study from the Mayo Clinic. That study found high levels of vitamin D did not increase the risk for elevated blood calcium levels, and that only one case of vitamin D toxicity was found in a decade-long study of more than 20,000 people.
Elizabeth Somer, M.A.,R.D.
Clemente-Postigo M, Munoz-Garach A, Serrano M, et al: Serum 25-hydroxyvitamin D and adipose tissue vitamin D receptor gene expression. Journal of Clinical Endocrinology & Metabolism 2015; February 23rd.
Dudenkov D, Yawn B, Oberhelman S, et al: Changing incidence of serum 25-hydroxyvitamin D values above 50 ng/mL. Mayo Clinic Proceedings 2015;90:577-586.