As of 2011, no evidence shows that vitamin D supplements affect blood sugar. Some studies suggest the vitamin has no effect on glucose while others point to the possibility that it may lower glucose and help patients who suffer from elevated levels. Before you begin taking vitamin D supplements in an attempt to benefit your health, ask your doctor first.
About Vitamin D
Vitamin D facilitates the absorption of calcium, a mineral essential to healthy bones, teeth, muscles and nerves. The nutrient also regulates the amount of calcium and phosphate in the blood stream, keeping it within normal range. A lack of vitamin D causes muscle problems as well as brittle bones in adults and a deformed skeletal structure in children.
About Glucose
Glucose is a carbohydrate, a sugar your body uses as a source of energy. It is present in foods of plant origin as starch. During digestion, your body breaks the starch down into glucose to feed your cells. The pancreas releases the hormone insulin to signal to the cells that the sugar is available for consumption. An elevated glucose level in the bloodstream indicates one of two situations: The gland is not able to produce enough insulin to induce your cells to absorb the sugar or your cells are desensitized to the hormone and do not get its message that food is available. Diabetes is an example of a condition where symptoms include high blood sugar.
Vitamin D and Glucose
The scientific evidence on the relationship between vitamin D and glucose swings in different directions, but it has not gone towards hyperglycemia, the medical term for too much sugar in the bloodstream. In an Iranian study reported in the "American Journal of Clinical Nutrition" in February 2011, diabetic individuals who ate yogurt fortified with vitamin D for 12 weeks experienced a glucose drop. Participants in the same clinical trial who had plain yogurt did not enjoy the same benefit. Another study published on the same day in the journal “Diabetes Care” concluded that postmenopausal women low on vitamin D were not at greater risk for developing diabetes type 2, in which hyperglycemia occurs because the cells cannot sense the presence of insulin. The latter research seems to indicate that vitamin D does not influence glucose level, contradicting the result of the Iranian study. That shows that more clinical trials need to be conducted to firmly establish the relationship between the two substances.
Precaution
Since evidence exists suggesting that vitamin D may lower glucose, do not supplement the nutrient if you take diabetes drugs or if you suffer from low blood sugar without talking to your doctor. The vitamin may take your glucose to an abnormally low level and cause hypoglycemia, a serious condition that can lead to seizures and coma.
References
- Office of Dietary Supplements: Vitamin D
- Office of Dietary Supplements: Calcium
- Elmhurst College; Glucose; Charles E. Ophardt; 2003
- AIDSinfo: Hyperglycemia
- “The American Journal of Clinical Nutrition”; Daily Consumption of Vitamin D--or Vitamin D + Calcium–fortified Yogurt Drink Improved Glycemic Control in Patients with Type 2 Diabetes: a Randomized Clinical Trial; Bahareh Nikooyeh, et al.; Feb. 2, 2011
- “Reuters”; Vitamin D May Help Keep Blood Sugar Under Control; Leigh Krietsch Boerner; Feb. 23, 2011
- “Diabetes Care”; Lack of Association Between 25(OH)D Levels and Incident Type 2 Diabetes in Older Women; Jennifer G. Robinson, M.D., M.P.H., et al.; Feb. 2, 2011
- PubMed Health; Hypoglycemia; Ari S. Eckman, M.D., et al.; June 28, 2011
