Understanding of the various ways vitamin D effects the body is growing rapidly. Originally this vitamin was thought to only effect calcium in the blood and bone but recent research shows it possesses important influences on the immune system and cancer development. A study just published in Journal of Endocrinology and Metabolism June 2012 now shows that this same vitamin can possibly influence metabolism. A common disorder of metabolism known as Syndrome X or the Metabolic Syndrome is characterized by high triglycerides and low good cholesterol (HDL), abdominal obesity, along with elevated blood pressure and blood sugar. The researchers discovered those with vitamin D levels between 16 and 20 were 75% more likely to develop the Metabolic Syndrome within 5 years than those with vitamin D levels above 34 (levels below 30 are considered low).
Whether low vitamin D is the cause of the Metabolic Syndrome is unclear. Vitamin D prevents fat cells from reproducing, helps the natural process of triglyceride breakdown and helps regulate blood sugar by making insulin work more efficiently. Without enough vitamin D the fat cells could multiply faster, triglyceride levels accumulate and blood sugar rise as is seen in Metabolic Syndrome.
As I have explained in previous posts at metabolism.com, vitamin D is also related to development of hardening of the arteries (atherosclerosis) and obesity in Type 2 Diabetes which could be considered a more advanced form of Metabolic Syndrome.
Doctorsâ€™ efforts to monitor vitamin D levels are being hindered by new regulations by Medicare and private insurance carriers to deny payment for vitamin D screening. Lately, a number of my patientsâ€™ vitamin D tests were denied by insurance carriers with patients being charged over $200 per test because it was not â€œindicatedâ€.
Recommendations for vitamin D supplementation are debated. When skin is exposed to sunlight it manufactures vitamin D so there is thought that people who get sun exposure should not need vitamin D supplement but that is not borne out in reality. Previously the recommended daily allowance (RDA) was 400 units per day an amount which has been increased slightly for the elderly. Some experts recommend 1000 unit daily or more. In my practice I generally recommend starting at 1000 units and then rechecking 25 hydroxy vitamin D levels a few months later. Some individuals require 4000 unit or more daily to achieve vitamin D levels over 30. When purchasing vitamin D the D3 form appears to be converted in the body more rapidly than the D2 variety. High priced brands of vitamin D, in my opinion, are a waste of money.
Gary Pepper, M.D.