According to the study's principal investigator, Stephanie Sisley, MD, "Our results suggest that Vitamin D may play a role in the onset of both obesity and Type 2 diabetes by its action in the brain."
The animals (rats) fasted, and had fasting blood sugar tested. The study then administered Vitamin D3 to obese male rates, directly to the hypothalamus. (A control group did not receive the Vitamin D3). An hour later, all the animals had a glucose tolerance test, after which their blood sugar levels were again measured.
The study showed that the animals receiving the Vitamin D3 had improved glucose tolerance and insulin sensitivity. (Insulin's job is the help process glucose out of the bloodstream, and decrease the liver's glucose production.) In the study, Vitamin D in the brain decreased the glucose created by the liver.
In another study, researchers gave Vitamin D for four weeks to one group, versus a control group that did not receive the vitamin. The group getting the Vitamin D ate three times less food, and lost 24 percent of their body weight, despite no increase in exercise or calorie expenditure. The control group did not lose any weight.
Dr. Sisley said: "Vitamin D is never going to be the silver bullet for weight loss, but it may work in combination with strategies we know work, like diet and exercise."
How Does Vitamin D Work?
According to Dr. Sisley, "The brain is the master regulator of weight." Specifically, the area of the brain known as the hypothalamus has receptors for Vitamin D, and hypothalamic function controls weight and glucose (blood sugar) levels in the body.
For more information on Vitamin D, see Dr. Kent Holtorf's YouTube video, discussing the role of Vitamin D.
What This Means For You?
We already know that Vitamin D is as much a hormone as it is a vitamin. Vitamin D deficiency contributes to autoimmune diseases like Hashimoto's thyroiditis and Multiple Sclerosis, Rheumatoid Arthritis and Scleroderma.
In addition, low Vitamin D levels are linked to:
- Increased risk of death from heart disease
- Cognitive impairment in seniors
- Cancer risk
- Osteoporosis and fracture risk
- Gestational diabetes, preeclampsia
A good starting point is to have your Vitamin D levels tested via a blood test. Don't accept a test result of "your levels are normal" from your practitioner, however. Ask for the actual number, and the reference range at the laboratory where your blood was tested. Keep in mind that levels in the bottom half of the reference range may be "normal," but are not optimal, and may warrant supplementation.