A review published in the July, 2006 issue of the American Journal of Clinical Nutrition which sought to determine the optimal serum levels of the major circulating form of vitamin D [25(OH)D] for several health outcomes concluded that it would be necessary to consume at least 1000 international units of vitamin D per day to elevate blood serum levels in half the adult population to 75 nanomoles per liter, the minimum level that the researchers found to be advantageous for helping to preserve normal bone mineral density and lower extremity function, and aiding in the prevention of periodontal disease, falls, fractures, and colorectal cancer.
Although there is evidence for vitamin D in preventing other diseases such as multiple sclerosis, tuberculosis, insulin resistance, osteoarthritis, hypertension, and cancers other than colorectal cancer, the authors did not include these diseases in the current review.
H. A. Bischoff-Ferrari of Harvard School of Public Health in Boston and University Hospital Zurich in Switzerland, along with colleagues at Harvard and Tufts University evaluated clinical trials and meta-analyses involving vitamin D and each of the selected health outcomes. They concluded that the most desirable serum levels of vitamin D began at 75 nanomoles per liter (30 nanograms per milliliter), and optimal levels are between 90 and 100 nanomoles per liter.
These levels cannot be reached by most individuals with the current recommended intakes of 200 international units per day for younger adults and 600 international units per day for older adults. To bring vitamin D concentrations in at least 50 percent of the population up to optimal levels, the authors recommend at least 1000 IU vitamin D per day, and they remark that 2000 IU per day may be a safe recommended daily allowance.
“On the basis of this review, we suggest that, for bone health in younger adults and all outcomes in older adults, including antifracture efficacy, lower-extremity strength, dental health, and colorectal cancer prevention, an increase in the current recommended intake of vitamin D may be warranted,” the authors conclude. “Given the low cost, the safety, and the demonstrated benefit of higher 25(OH)D concentrations, vitamin D supplementation should become a public health priority to combat these common and costly chronic diseases.”
Related Health Concern: Periodontitis and Cavities
Periodontal diseases, including gingivitis and periodontitis, are inflammatory diseases that affect the supporting structures that anchor the teeth in place (periodontium). Gingivitis and periodontitis are related conditions: if left untreated, gingivitis, or inflammation of the gingival tissue (gums), can progress to periodontitis, a more serious condition. Gingivitis is a treatable and reversible condition, while periodontitis is an irreversible condition that can lead to tooth loss.
Vitamin C has long been known for its ability to prevent gum disease and tooth loss. In fact, the use of vitamin C in dental disease is one of the earliest recorded uses of nutrient therapy in Western medicine. In 1747, a British Naval physician named James Lind noticed that lime juice, which is rich in vitamin C, helped prevent scurvy, which causes tooth loss. As a result, British sailors bottled lime juice for gum disease prevention. Incidentally, this practice later gave rise to the term “Limey.”
Researchers have also examined the value of vitamin D and calcium, which are typically used to reduce the risk of osteoporosis. Supplementation with these two nutrients reduces the rate of bone and tooth loss in postmenopausal women and men. Calcium intake of 800 mg or more per day reduced the risk of periodontitis in females (Nishida M et al 2000).
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