Despite its name, Vitamin Dis not a vitamin, but a steroid hormone made in the skin from cholesterol stimulated by ultraviolet light B. It occurs naturally in some animal products: egg yolks, fatty meat, and liver. In addition, many cereal and milk brands sold in the United States are fortified by vitamin D.
Vitamin D’s role in many medical conditions is now being discovered in recent research. Many disease states attributed to “aging” are actually linked to inadequate levels of Vitamin D in the blood. The well known condition Osteoporosis (brittle bones), is common in older women and some men. Part of the treatment for Osteoporosis is correcting the Vitamin D deficiency in addition to correcting other hormone deficiencies.
A double blind randomized trial showed that higher levels of vitamin D correlates with reduction in falling by 22% ( JAMA, 2004). It is not known whether Vitamin D status and muscle strength are causally related, but it is clear that both older men and women experience less falls if their vitamin D level is adequate.
Another study of women 40 years of age and older showed that the higher the Vitamin D level is, the less risk of overactive bladder. (Neurourology,2004).
Lung function is known to decline with age. The National Health and Nutrition Examination Survey Ill (NHANES Ill) studied group of people, 60 years of age and older, and found that lung function was significantly higher among those with higher quintile of serum Vitamin D concentration. (Chest,2005). Biologically plausible ways in which vitamin D can protect lung function is by preventing respiratory muscle loss, helping in remodeling of lung tissue and reducing airway inflammation.
In the same NHANES Ill study, the risk of developing an age related macular degeneration declined with increasing vitamin Din blood levels: the higher the blood level of vitamin D was, there was less of an incidence of developing of macular degeneration.
Increasing levels of serum vitamin D may reduce the risk of breast cancer (Cancer Epidemiology, 2005). Moreover, women with blood levels of vitamin D more than SO were less likely to develop breast cancer in the first place (European journal of cancer, 2005). This blood level correlates on average with the intake of vitamin D of 4000 – 5 0000 IU. Evidence also suggests decreasing risk of colorectal cancer with increasing level of vitamin D in the blood.
Metabolic syndrome, nowadays a common condition leading to diabetes and cardiovascular mortality, appears to be positively influenced by adequate Vitamin D level as well.
The risk of coronary disease (acute myocardial infarction) was assessed in men in relationship to the level of vitamin D. After adjusting for other risk factors (like high serum cholesterol, family history of heart disease, obesity, alcohol, smoking, etc) the conclusion was made that men with low levels of vitamin D had more heart attacks than men with higher levels (Archives of Internal Medicine, 2008). Same researchers stipulate that current guidelines of supplementing vitamin D should be increased up to 10 000 IU per day based on individual blood levels.
“18 study meta-analysis” published in Archives of Internal Medicine in 200 7 describes the impact of vitamin D supplementation in lowering ALL CAUSE MORTALITY.
Annals of Epidemiology article stipulates based on more than 3,000 scientific articles, that raising serum level of vitamin D 3 to 40-60 in the adult population of the US and Canada, will reduce 58,000 cases per year of breast cancer and 49,000 cases of colorectal cancer.
Most laboratories give normal range for vitamin D3 level 30-100. It is clear from these studies that optimal levels are probably 50- 70. Should we worry about toxicity of vitamin D if the level is approaching 100? The answer is NO. There was one case of toxicity described in the medical literature where the patients were taking mislabeled supplements. As a result, their levels were above 400. None of the patients suffered any consequences or required any specific treatment. Simple discontinuation of faulty supplement resulted in lowering the level to normal.
In my practice, I measure the blood level of vitamin D3 in all my patients at least once a year. For those patients whose levels are below 50, I recommend a supplemental vitamin D 3 from a reliable company (such as MD Prescriptives) and then recheck the level in 2-3 months (desired range of vitamin D 3 is 50-70). Since my practice is located in Florida, I’m frequently asked whether it is enough to just go on the sun. I advise against it for two reasons: 1.excessive sun exposure often results in precancerous and cancerous skin lesions and wrinkles, 2. Even in “sun worshippers” the blood level of vitamin Dis surprisingly inadequate. Oral supplements are simple, safe and does the job.