Vitamin D insufficiency and chronic diseases: hype and reality.
In recent years an increasing number of observational studies have suggested that a low vitamin D status contributes to the development of all sorts of chronic diseases. In reality, however, studies that had been adequately controlled for confounding factors ruled out any link between vitamin D insufficiency and, for example, metabolic disorders, arterial hypertension, multiple sclerosis or cognitive dysfunction. Furthermore, a role of vitamin D insufficiency in autoimmune diseases is evident only in animal models but has not yet been established in humans. In respect to many malignancies, vitamin D insufficiency is only one out of many risk factors and its specific impact on disease incidence has never been assessed. There is convincing evidence, however, that vitamin D insufficiency is a major risk factor for osteoporosis, colorectal and breast cancer as well as for cardiovascular disease and mortality. However, it is debatable that circulating 25-hydroxyvitamin D concentrations of 100-150 nmol l(-1) are required for optimal health outcomes. These are overestimates which would afford to raise vitamin D intake to 4000 IU day(-1). In reality, high doses of vitamin D can cause serious health problems because of the U-shaped dose-response relationships that exist in some cases. Data from large cohort studies clearly indicate that serum 25-(OH)D concentrations around 50 nmol l(-1) are sufficient to minimize the risk of osteoporotic fractures, colorectal and breast cancer, and cardiovascular mortality. The fact that the risk-reducing potential of vitamin D depends on adequate calcium nutrition is widely ignored. I here summarize the evidence that efficient disease prevention does not require intake of more vitamin D and calcium than currently recommended for maintaining optimal bone health.
Medical University of Vienna, Department of Pathophysiology, Waehringer Guertel 18-20, A-1090 Vienna, Austria. meinrad.peterlik@meduniwien.ac.at
Meinrad
M
Peterlik
D000818:Animals; D001943:Breast Neoplasms / Q000517:prevention & control; D002136:Calcium, Dietary / Q000008:administration & dosage; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002908:Chronic Disease / Q000517:prevention & control; D015179:Colorectal Neoplasms / Q000517:prevention & control; D004032:Diet; D019587:Dietary Supplements / Q000009:adverse effects; D006801:Humans; D010024:Osteoporosis / Q000517:prevention & control; D012016:Reference Values; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications / Q000235:genetics
D002136:Calcium, Dietary; D014807:Vitamin D; C104450:25-hydroxyvitamin D