Vitamin D helps the body perform numerous functions including working with calcium to enhance bone strength. While the precise role of vitamin D in weight control is uncertain, several studies suggest that this fat-soluble vitamin promotes weight loss. For example, if you have low levels of vitamin D you are more likely to be obese than a person who has a sufficient level, note the experts at University of Maryland Medical Center. Always consult a doctor before trying a new supplement.
Vitamin D may help prevent malfunctions of the parathyroid hormones and is used to treat disorders of the parathyroid glands. The four parathyroid glands in the neck produce parathyroid hormone, which helps your body store and use calcium and phosphorus. An underactive parathyroid gland can increase your chances of developing hypothyroidism, or underactive thyroid, according to University of Pittsburgh Medical Center.
Hypothyroidism disturbs the normal balance of chemical reactions in your body. When left untreated it can lead to weight gain and obesity.
Vitamin D levels may predict your ability to lose fat, especially in the abdominal region, according to the June 15, 2009 article, “U Study: Vitamin D Connected to Weight Loss,” by Jessica Van Berkel published in the University of Minnesota publication MNDaily.com. Even though vitamin D deficiency has been linked to obesity, it's uncertain whether inadequate levels lead to weight gain or whether weight gain leads to low levels of vitamin D, UM researcher Shalamar Sibley notes in the article.
Also, research published in the January 2009 “Journal of Endocrinology and Metabolism” found that vitamin D deficiency is associated with increased body fat, according to lead author R. Kremer of McGill University in Canada.
Vitamin D Toxicity
Excess levels of vitamin D can be toxic, according to the National Institutes of Health Office of Dietary Supplements. The safe upper limit of vitamin D intake is 4,000 international units per day for ages 9 and over, including pregnant women. Vitamin D toxicity is caused solely by overuse of supplements, as the ODS explains that the body limits the amount of vitamin D it produces. Symptoms of vitamin D toxicity include nausea, vomiting, confusion, constipation and weight loss.
Higher intake of vitamin D and calcium can promote weight loss in overweight people who are dieting, according to a study published in the November 2010 "American Journal of Clinical Nutrition." The study followed obese participants with a body mass index, or BMI, of 31 over a two-year period. A BMI of 30 or greater is considered obese. Higher dairy calcium intake along with increased vitamin D was associated with greater diet-induced weight loss, according to lead study author D.R. Shahar.
Sources and Recommendations
Sunlight stimulates the production of vitamin D in the epidermis or outer layer of your skin. Sun exposure can provide most people with a sufficient amount of vitamin D. Since it's hard for people living in northern climates to get an ample amount vitamin D from sunlight during the winter you may need to take vitamin D supplements if you live in one, explains the University of Maryland Medical Center.
Multivitamins typically include 400 IU of vitamin D, which is the recommended daily intake for adults, according to Oregon State University's Linus Pauling Institute.
Dietary sources of vitamin D include salmon and sardines. Milk and infant formula are fortified with vitamin D.
- American Journal of Clinical Nutrition: Dairy Calcium Intake, Serum Vitamin D, and Successful Weight Loss; D.R. Shahar et al.; 2010
- Journal of Endrocrinology and Metabolism: Vitamin D Status and its Relationship to Body Fat, Final Height, and Peak Bone Mass in Young Women; R. Kremer et al.; 2009
- Oregon State University Linus Pauling Institute: Vitamin D
- National Institutes of Health Office of Dietary Supplements: Vitamin D
- Medline Plus: Vitamin D
- University of Maryland Medical Center: Vitamin D