Can Vitamin D Help Control Weight and Blood Glucose?
Clinical trials will show whether the relationship between vitamin D and Observational research shows that blood glucose levels rise in the. Before adding any vitamins or adding dietary supplements to your daily diet, . by high blood sugar levels, may be associated with deficiency of vitamin B6, also . We used a multivariate logistic regression model to predict the relationship between glucose control and vitamin D deficiency. We used race/ethnicity, BMI, age.
Some day — maybe soon — having your vitamin D level measured may become as routine as having your cholesterol checked.
According to some advocates of routine vitamin D testing, the results could prove to be a useful piece of medical information. The importance of adequate vitamin D levels in the body has been recognized for decades.
It was later discovered that it is the vitamin D produced when the skin is exposed to sun that helps the body absorb calcium and strengthen the skeleton.
Around the same time, cod liver oil was found to be a potent food source of vitamin D. Advertisement Recently, however, new research on the so-called sunshine vitamin has shown that it plays a role in many more bodily systems than just the skeletal system. In fact, a deficiency of vitamin D is thought to possibly play a role in the development of numerous diseases, from cardiovascular disease to multiple sclerosis to complications of pregnancy.
All of this new attention has made vitamin D a very popular supplement and the subject of renewed scientific inquiry. Vitamin D in the body The human body was designed to get most of its vitamin D through exposure to the ultraviolet UVB rays of the sun — the same rays that cause sunburn and skin damage.
Cholesterol is produced by the liver, so consuming dietary cholesterol is not necessary for vitamin D production. UVB rays set off a chain reaction in exposed skin that continues in the liver and finishes in the kidneys, where vitamin D is activated and sent out to tissues throughout the body. Active vitamin D is one of many body hormones, chemical messengers that regulate body functions. Vitamin D can also be found in food or supplements and is absorbed like a dietary fat.
Both dietary and sun-derived D are stored in fat tissue. This means the body has some capacity to store the vitamin for later use. Active vitamin D, also known as 1,dihydroxycholecalciferol, calcitriol, or vitamin D3, has many functions. Some of the known functions are well understood, such as how vitamin D helps the body absorb calcium and how it hardens bones and teeth. Other functions, such as how it helps regulate the immune system, are still being studied and learned about.
What is known is that almost every cell in the body has vitamin D receptors, suggesting that it must have a role in all of them.
Particularly interesting in diabetes is that the insulin-producing beta cells in the pancreas not only have the ability to accept vitamin D, but also to activate it, just as the kidneys do.
Vitamin D and diabetes Deficiency of vitamin D has been associated with both Type 1 and Type 2 diabetes and with metabolic syndrome a combination of high blood pressureabnormal blood cholesterol and triglyceride levelsinsulin resistanceand excess abdominal fat that often precedes or goes along with Type 2 diabetes.
While it is yet to be fully understood how vitamin D helps the body regulate blood glucose, there seem to be several ways.
The impact of Vitamin D Replacement on Glucose Metabolism
Because vitamin D is present in the insulin-producing beta cells, and insulin secretion is calcium dependent and therefore indirectly vitamin D dependentit is theorized that vitamin D has a direct effect on how much insulin the body makes. Both in vitro studies studies done on cells in a laboratory and animal studies have shown that vitamin D deficiency impairs insulin secretion and that correcting vitamin D status restores the function.
Furthermore, when insulin is released, it must make contact with insulin receptors on cells to lower blood glucose.
Other laboratory studies have shown that vitamin D may help the body produce and activate these insulin receptors. Finally, diabetes and other chronic conditions are associated with increased levels of inflammation throughout the body, which may be the root of some of their long-term complications such as atherosclerosis hardening of the arteries. Vitamin D and calcium are both shown to reduce the production of inflammatory chemicals in the body called cytokines. With so much evidence of a role for vitamin D in regulating blood glucose levels, the obvious question is whether vitamin D can prevent, cure, or treat diabetes.
Several large observational studies have shown that vitamin D intake might prove to be a preventative factor in diabetes. Further strengthening the notion of this relationship, the children in the study who had suspected rickets had the highest rates of Type 1 diabetes.
Can Vitamin D Help Control Weight and Blood Glucose?
Also, because this was only an observational study, one cannot assume this tremendous risk reduction from supplements for all children. Apparent risk reduction has also been shown with Type 2 diabetes. These are promising reports, but to prove that vitamin D helps prevent diabetes, clinical trials, or studies on humans, are still needed.
Clinical trials will show whether the relationship between vitamin D and diabetes is direct or indirect. They will also determine whether high levels of vitamin D protect women from Type 2 diabetes, or whether women who lead the types of healthy lifestyles that help prevent Type 2 diabetes getting lots of outdoor activity, for example just happen to have higher levels of vitamin D.
The few intervention studies in which vitamin D has been administered in hopes of reversing diabetes have not been successful. But what about using vitamin D to help manage diabetes? Observational research shows that blood glucose levels rise in the winter, which is when vitamin D levels fall. The few human intervention studies that have been done to try to establish cause and effect have been inconclusive.
Vitamins and Minerals for Diabetes
N Engl J Med ; Alvarez JA, Ashraf A. Role of vitamin D in insulin secretion and insulin sensitivity for glucose homeostasis. Int J Endocrinol ; Teegarden D, Donkin SS. Nutr Res Rev ; Association of A1C levels with vitamin D status in U. Baseline serum hydroxyvitamin D is predictive of future glycemic status and insulin resistance: Aging decreases the capacity of human skin to produce vitamin D3.
J Clin Invest ; An evaluation of the relative contributions of exposure to sunlight and of diet to the circulating concentrations of hydroxyvitamin D in an elderly nursing home population in Boston.
Am J Clin Nutr ; Intestinal cholecalciferol absorption in the elderly and in younger adults. Clin Sci Mol Med ; Use and abuse of HOMA modeling. High latitude and marine diet: Br J Nutr ; Reduced antibody responses to vaccinations in children exposed to polychlorinated biphenyls.
Serum vitamin D and subsequent occurrence of type 2 diabetes. Diagnostic and therapeutic implications of relationships between fasting, 2-hour postchallenge plasma glucose and hemoglobin a1c values.
Arch Intern Med ; Vitamin D and diabetes. J Steroid Biochem Mol Biol ; Vitamin D status and glucose homeostasis in the British birth cohort: Adiposity, cardiometabolic risk, and vitamin D status: Decreased bioavailability of vitamin D in obesity. Relationships of low serum vitamin D3 with anthropometry and markers of the metabolic syndrome and diabetes in overweight and obesity.
Associations of serum concentrations of hydroxyvitamin D and parathyroid hormone with surrogate markers of insulin resistance among U. Association between type of dietary fish and seafood intake and the risk of incident type 2 diabetes: Dietary omega-3 fatty acids and fish consumption and risk of type 2 diabetes.
Tracking of serum hydroxyvitamin D levels during 14 years in a population-based study and during 12 months in an intervention study. Am J Epidemiol ; New aspects of HbA1c as a risk factor for cardiovascular diseases in type 2 diabetes: J Intern Med ;