Low Vitamin D Linked to Poor Diabetes Control
Study Finds Vitamin D Deficiency Common in People With Diabetes
WebMD News Archive
Vitamin D Facts
Vitamin D is crucial not only to maintain bone strength, but research also suggests it plays a role in immune system functioning, cancer prevention, and cardiovascular health. It is produced when ultraviolet rays from the sun strike the skin and is also found in fish, eggs, fortified milk, cod liver oil, and supplements.
Adequate intakes, set by the Institute of Medicine of The National Academies, are 200 international units (IU) a day for adults up to age 50, 400 IU for people aged 51-70, and 600 IU for people 71 and older. But some experts say much more is needed; the recommendations are under review, with an update expected in 2010.
The new study lends support to a growing body of scientific and clinical data linking vitamin D with insulin and glucose, says Ruchi Mathur, MD, an endocrinologist and assistant professor of medicine at Cedars-Sinai Medical Center, Los Angeles, who reviewed the study for WebMD.
Other research has shown that supplementing with vitamin D and calcium slows the progression to type 2 diabetes, Mathur says. Even so, she tells WebMD, ''At present, a direct link between vitamin D and type 2 diabetes is not conclusively established."
She has another caveat. ''One important point that is missing ... is the prevalence of vitamin D deficiency in the general population" compared to those in the study. As vitamin D deficiency is being noted with ''an alarming increase in frequency'' overall, she says, ''it may shed doubts on the authors' conclusions."
It's also possible, she says, that people with poor glycemic control have it because of a general unhealthy lifestyle, not just their low vitamin D status. They may engage in less outdoor exercise, for instance, or have unhealthy eating habits.
Because of the possible link, however, she agrees that screening for vitamin D deficiency in people with type 2 diabetes may be warranted.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.