The relationship between vitamin D deficiency and hypoglycemia is a bit puzzling. Hypoglycemia refers to a condition in which blood sugar, or glucose, levels are too low, but diabetes is a disease caused by glucose levels that are too high. Yet researchers report protective benefits from vitamin D intake suggesting that deficiency would lead to high blood sugar rather than low. However, there are some circumstances under which deficiency seems to contribute to hypoglycemia.
Researchers reporting in the November 2008 issue of "The Diabetes Educator" reviewed the major clinical trials and populations studies investigating vitamin D and blood sugar in both diabetics and nondiabetics. The researchers concluded that vitamin D is especially important in diabetics by helping to decrease sugar in the blood. Further, vitamin D exerts a protective effect by lowering the risk of developing diabetes in healthy people. One study the reviewers analyzed recommended research into vitamin D supplementation as a means to help keep blood sugar levels in check.
Researchers reporting in the September 2009 issue of the "European Journal of Clinical Nutrition" accepted the challenge to investigate whether vitamin D supplementation would lower glucose in Type 2 diabetics. While diabetics are commonly vitamin D deficient, the researchers were careful to enroll patients with normal levels. Thirty-six insulin-dependent subjects were divided into two groups, one of which received 40,000 IU of vitamin D per week for six months, the other placebos. At the end of the trail, vitamin D had no impact on glucose. However, the researchers indicated that results may differ in patients who are deficient in vitamin D.
Glycogen Storage Disease
There is some direct evidence that vitamin D deficiency can produce dangerously low glucose levels. The relationship was found in studies that examined the causes of glycogen storage disease. Before describing the evidence, though, it's important to understand a little about the disease and glycogen. Glycogen is the main way in which the body stores glucose for later use. It's a chain of up to thousands of individual glucose molecules that is fabricated in the liver and stored in muscle and fat cells, as well as in the liver. Glycogen storage disease is a disorder in which something goes wrong during glycogen fabrication.
Hypovitaminosis D is the medical term for vitamin D deficiency, and researchers reporting in the April 2010 issue of "Molecular Genetics and Metabolism" linked it to faulty glycogen metabolism. Hypoglycemia is a symptom of glycogen storage disease, and the researchers noted a high prevalence of hypovitaminosis D amongst patients. The researchers supplemented 26 patients with 400 IU of vitamin D daily for six months in an attempt to bring their blood levels up to normal. However, their vitamin D levels didn't budge, leading the researchers to suggest that an inability to properly synthesize vitamin D causes hypoglycemia.