Vitamin D, sometimes called the "sunshine vitamin," frequently finds itself in the media limelight. Low levels of this high-profile nutrient have been associated with everything from poor bone health to certain cancers. It now appears that there may be a link between inadequate vitamin D and type 2 diabetes.
About Vitamin D
Your body manufactures vitamin D when your skin is exposed to the ultraviolet light of the sun. Natural dietary sources of the vitamin are relatively few and include certain fish, egg yolks, liver and beef. Vitamin D is also added to certain foods like milk, fortified juices and cereals. In your body, vitamin D helps you absorb calcium from the gut into the circulatory system, and it helps ensure the proper balance of calcium in the bones and in the bloodstream. It also has roles in muscle movements, cell growth and immune system functions. Because many people do not spend much time outdoors, and because dietary sources of the vitamin are limited, certain populations may run the risk of having low vitamin D levels.
Who is at Risk?
According to Medline Plus, a service of the National Institutes of Health, individuals at risk for having low levels of vitamin D include senior citizens, breast-fed babies, dark-skinned people, those who get little exposure to sunlight, obese people, people who do not absorb nutrients well due to inflammatory bowel disease, cystic fibrosis or other health issues and people who take steroid medications. If one or more of these conditions applies to you, take a vitamin D supplement. Since there are also health consequences to taking excessive vitamin D, discuss supplement strategies with your health-care provider.
The Diabetes Connection
Australian researchers followed more than 5,000 people over five years and discovered that those with low vitamin D levels had a significantly greater risk of developing type 2 diabetes than people with levels in the recommended range. This study, published in the March 23, 2011, journal "Diabetes Care," found that, after adjusting for other risk factors like age, waist circumference and family history of the disease, there was a 57 percent increased risk of developing type 2 diabetes in those with low levels of vitamin D compared to those with normal levels. Authors of the study were quick to point out that even though an association was found between low vitamin D levels and type 2 diabetes, the association does not prove a cause and effect relationship.
Practical Measures
The Canadian Dermatology Association warns that too much exposure to the sun can lead to skin cancer, premature wrinkles and other undesirable effects. Even brief exposure of the face, hands and arms to the sun's rays two to three times per week can be adequate during the sunny seasons. Oral vitamin D supplements can be considered during the winter months, particularly for the elderly. The association also advises against using tanning beds to boost your levels of vitamin D.
References
- Medline Plus: Are You Getting Enough Vitamin D?
- "Diabetes Care"; Serum 25-Hydroxyvitamin D, Calcium Intake, and Risk of Type 2 Diabetes After 5 Years; C. Gagnon, Z. Lu, D. Magliano, et al; March 23, 2011
- Canadian Dermatology Association: Sun Exposure and Healthy Levels of Vitamin D
