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Vitamin D deficiency: a worldwide problem with health consequences. Holick MF, Chen TC. Am J Clin Nutr. 2008 Apr;87(4):1080S-6S. Review. PMID: 18400738 A reevaluation needs to take place of what the adequate intakes of vitamin D should be for children and adults. The literature over the past decade suggests that the Institute of Medicine recommendations in 1997 (83) are inadequate, and some experts including us suggest that both children and adults should take ≥800-1000 IU vitamin D/d from dietary and supplemental sources (4, 9, 77) when sunlight is unable to provide it. This recommendation, however, has not yet been embraced either by official government or pediatric organizations in the United States, Canada, or Europe for either children or adults.

Fatigue fractures in military conscripts : A study on risk factors, diagnostics and long-term consequences Ruohola, Juha-Petri University of Helsinki, Faculty of Medicine, Institute of Clinical Medicine, Orthopaedics and Traumatology, Helsinki University Central Hospital Centre of Military Medicine, Helsinki 2007-03-09 Doctoral dissertation (article-based) It seems likely that low vitamin D levels are related to fatigue fractures, and that an increasing trend exists between TRACP-5b bone resorption marker elevation and fatigue fracture incidence. Though seldom detected by plain radiography, fatigue fractures often underlie unclear lower leg stress-related pain occurring in the distal parts of the tibia. Femoral neck fatigue fractures, when displaced, lead to long-term morbidity in a high percentage of patients, whereas, when non-displaced, they do not predispose patients to subsequent adverse complications. Importantly, an educational intervention can diminish the incidence of fracture displacement by enhancing awareness and providing instructions for earlier diagnosis of fatigue fractures

Not enough vitamin D: health consequences for Canadians. Schwalfenberg G. Can Fam Physician. 2007 May;53(5):841-54. Review PMID: 17872747 Conclusion Low levels of VTD are considered a major public health problem in Canada, especially during the winter. Those with risk factors should be screened for low 25(OH)D levels and repletion therapy instituted if needed. Researchers have estimated that the oral dose of vitamin D3 to attain and maintain 25(OH)D levels >80 nmol/L is 2200 IU/d if baseline levels are 20 to 40 nmol/L, 1800 IU/d if levels are 40 to 60 nmol/L, and 1160 IU/d if levels are between 60 and 80 nmol/L.64 We need to ensure that patients have healthy blood levels of 25(OH)D to prevent levels of parathyroid hormone from rising and to maximize absorption of calcium, magnesium, and phosphate. Positive effects on bone are marginal at best unless patients consume at least 800 IU/d of VTD. The emerging and exciting role of the VTD receptor and the actions of VTD in maintaining health in other cell types have become more apparent during the last decade.

Not enough vitamin D: health consequences for Canadians.\nSchwalfenberg G.\nCan Fam Physician. 2007 May;53(5):841-54. Review.\nPMID: 17872747 \n

The Vitamin D Pandemic and its Health Consequences\nPresented by Michael Holick, PhD, MD, Professor of medicine, physiology and biophysics and director of the General Clinical Research Center at Boston University Medical Center\nKeynote address at the opening ceremony of the 34th European Symposium on Calcified Tissues, Copenhagen 5 May, 2007\n

Holick MF. The vitamin D epidemic and its health consequences. J Nutr. 2005 Nov;135(11):2739S-48S. PMID: 16251641 [PubMed - indexed for MEDLINE]

Factors that influence the cutaneous synthesis and dietary sources of vitamin D. Chen TC, Chimeh F, Lu Z, Mathieu J, Person KS, Zhang A, Kohn N, Martinello S, Berkowitz R, Holick MF. Arch Biochem Biophys. 2007 Apr 15;460(2):213-7. Epub 2007 Jan 8. PMID: 17254541 doi: 10.1016/j.abb.2006.12.017 Vitamin D is rare in food. Among the vitamin D-rich food, oily fish are considered to be one of the best sources. Therefore, we analyzed the vitamin D content in several commonly consumed oily and non-oily fish. The data showed that farmed salmon had a mean content of vitamin D that was ~25% of the mean content found in wild caught salmon from Alaska, and that vitamin D2 was found in farmed salmon, but not in wild caught salmon. The results provide useful global guidelines for obtaining sufficient vitamin D3 by cutaneous synthesis and from dietary intake to prevent vitamin D deficiency and its health consequences.ensuing illness, especially, bone fractures in the elderly.

Robert P. Heaney is John A. Creighton University Professor, Creighton University, Omaha, Nebraska, United States. Hominid evolution took place in an environment (equatorial East Africa) that provided a superabundance of both calcium and vitamin D, the first in available foods and the second through conversion of 7-dehydrocholesterol to pre-vitamin D in the skin, a reaction catalysed by the intense solar ultraviolet (UV) radiation. Seemingly as a consequence, the evolving human physiology incorporated provisions to prevent the potential of toxic excesses of both nutrients. For vitamin D the protection was of two sorts: skin pigmentation absorbed the critical UV wavelengths and thereby limited dermal synthesis of cholecalciferol; and slow delivery of vitamin D from the skin into the bloodstream left surplus vitamin in the skin, where continuing sun exposure led to its photolytic degradation to inert compounds. For calcium, the adaptation consisted of very inefficient calcium absorption, together with poor to absent systemic conservation. The latter is reflected in unregulated dermal calcium losses, a high sensitivity of renal obligatory calcium loss to other nutrients in the diet and relatively high quantities of calcium in the digestive secretions. Today, chimpanzees in the original hominid habitat have diets with calcium nutrient densities in the range of 2 to 2.5 mmol per 100 kcal, and hunter-gatherer humans in Africa, South America and New Guinea still have diets very nearly as high in calcium (1.75 to 2 mmol per 100 kcal) (Eaton and Nelson, 1991). With energy expenditure of 3 000 kcal per day (a fairly conservative estimate for a contemporary human doing physical work), such diets would provide substantially in excess of 50 mmol of calcium per day. By contrast, median intake in women in North America and in many European countries today is under 15 mmol per day. Two factors altered the primitive situation: the migration of humans from Africa to higher latitude

Despite inadequacies in information concerning the minimum prophylactic requirement of vitamin D for all age groups beyond infancy, there is no doubt that a total intake of 400 I.U. per day is adequate to prevent vitamin D deficiency in substantially all normal children from birth through adolescence. Evidence derived from the study of idiopathic hypercalcemia suggests that certain infants excessively sensitive to the toxic action of vitamin D may, on rare occasions, be adversely affected by daily intakes of 3,000 to 4,000 I.U. and sometimes considerably less. Because of the prevalent practice of food fortification in the United States and Canada, there is now a definite possibility that the individual, even the young infant, may ingest considerably more than the recommended vitamin D allowance, and intakes of 2,000 to 3,500 I.U. per day are possible, particularly beyond infancy. Although there has been no specific evidence that intakes of this order produce deleterious effects beyond infancy, it is pointed out that the long-term consequences of this new nutritional situation on older children or adults are entirely unknown.

Low vitamin D status, high bone turnover, and bone fractures in centenarians. Passeri G, Pini G, Troiano L, Vescovini R, Sansoni P, Passeri M, Gueresi P, Delsignore R, Pedrazzoni M, Franceschi C. J Clin Endocrinol Metab. 2003 Nov;88(11):5109-15. PMID: 14602735 We conclude that the extreme decades of life are characterized by a pathophysiological sequence of events linking vitamin D deficiency, low serum calcium, and secondary hyperparathyroidism with an increase in bone resorption and severe osteopenia. These data offer a rationale for the possible prevention of elevated bone turnover, bone loss, and consequently the reduction of osteoporotic fractures and fracture-induced disability in the oldest olds through the supplementation with calcium and vitamin D.

Urgent action needed to improve vitamin D status among older people in England! Hirani V, Tull K, Ali A, Mindell J. Age Ageing. 2009 Nov 23. [Epub ahead of print] PMID: 19934073 CONCLUSIONS: poor vitamin D status of older people continues to be a public health problem in England. Hypovitaminosis D is associated with many risk factors and poor health outcomes. There is now an urgent need for a uniform policy on assessment and dietary supplementation of vitamin D in older people to prevent poor vitamin D status and its negative consequences

Vitamin D and mortality in older men and women. Pilz S, Dobnig H, Nijpels G, Heine RJ, Stehouwer CD, Snijder MB, van Dam RM, Dekker JM. Clin Endocrinol (Oxf). 2009 Nov;71(5):666-72. Epub 2009 Feb 18. PMID: 19226272 DOI: 10.1111/j.1365-2265.2009.03548.x Conclusions Low 25(OH)D levels are associated with all-cause mortality and even more pronounced with cardiovascular mortality, but it remains unclear whether vitamin D deficiency is a cause or a consequence of a poor health status. Therefore, intervention studies are warranted to evaluate whether vitamin D supplementation reduces mortality and cardiovascular diseases.