Metabolic syndrome has reached epidemic proportions in the United States, with more than one-third of all Americans having it, according to the Linus Pauling Institute. It is defined by the presence of three or more of the following conditions: hypertension, central obesity, high triglycerides, low HDL -- or good cholesterol -- and high blood glucose. Researchers have noted a link between metabolic syndrome and low levels of vitamin D.Check with your doctor before taking vitamin D or any other dietary supplement.
Diagnostic Criteria
If you have metabolic syndrome, you're at heightened risk for diabetes, heart disease and stroke. To be diagnosed with the syndrome, your test results must include: an HDL reading lower than 40 mg/dL for men and 50 mg/dL for women; a triglyceride level higher than 150 mg/dL; fasting blood sugar of more than 100 mg/dL, indicating glucose intolerance or insulin resistance; blood pressure higher than 130/85 mmHg; and abdominal obesity, with an abdominal circumference of more than 35 inches for women and 40 inches for men.
Insulin Resistance
Insulin resistance is strongly linked to vascular disease, notes a 2006 review published in "The Journal of Clinical Investigation," by C.F. Semenkovich, which helps explain IR's role in metabolic syndrome. In your body, insulin's job is to "unlock" the cells to allow glucose to enter. If the cells develop an insensitivity to insulin, they remain locked and the glucose continues to circulate in your bloodstream, causing hyperglycemia, or increased blood glucose. The glucose is stored as fat, usually around your waistline. The excess fat contributes to elevated triglycerides and low HDL. In turn, this increases your risk for vascular disease. It is unclear why the cells become desensitized, but a strong genetic factor appears to be at play, the review states.
About Vitamin D
Your skin can synthesize vitamin D from ultra-violet rays. You can also get it by eating certain foods or taking vitamin D supplements. Vitamin D plays a number of roles in your body, including maintaining calcium balance, inhibiting cell proliferation as seen in cancer cells, moderating blood pressure and regulating genes in human tissues, including the pancreas, where insulin is made.
The Vitamin D Connection
The link between insulin resistance and the other factors that contribute to metabolic syndrome is so strong that it is sometimes referred to as insulin resistance syndrome. For reasons yet unclear, vitamin D seems to alleviate insulin resistance. Researchers tested more than 3,000 middle-aged and elderly Chinese adults for serum vitamin D, glucose, insulin and cholesterol levels. Among those with the lowest vitamin D levels, the markers for metabolic syndrome and insulin resistance were significantly more common, according to a 2010 study by L. Lu and associates, in the journal "Diabetes Care."
References
- Linus Pauling Institute: Metabolic Syndrome
- MayoClinic.com: Metabolic Syndrome
- "The Journal of Clinical Investigation"; Insulin resistance and atherosclerosis; Clay F. Semenkovich; July 2006
- "Diabetes Care"; Plasma 25-hydroxyvitamin D concentration and metabolic syndrome among middle-aged and elderly Chinese individuals.; L.Lu,et al.; Jan. 2010
- "The American Journal of Clinical Nutrition"; Hypovitaminosis D is associated with insulin resistance; Ken C Chiu, et al.; 2004
Member Comments