caa a22 4500 388062231 CHVBK 20180307125124.0 cr unu---uuuuu 161130e199804 xx s 000 0 eng 10.1079/BJN19980055 doi S0007114598000567 pii (NATIONALLICENCE)cambridge-10.1079/BJN19980055 Boucher B. J. Academic Medical Unit and Cellular Mechanisms Research Group, St. Bartholomew's and the Royal London Hospital Medical & Dental School, Queen Mary Westfield, London El 1BB, UK Inadequate vitamin D status: does it contribute to the disorders comprising syndrome ‘X'? [Elektronische Daten] [B. J. Boucher] Environmental factors are important in the aetiology of glucose intolerance, type II diabetes and IHD. The lack of vitamin D, which is necessary for adequate insulin secretion, relates demographically to increased risk of myocardial infarction. These disorders are connected, degenerative vascular disease increasing with glucose intolerance and diabetes and, with its risk factors, comprising syndrome ‘X'. Evidence is presented suggesting that vitamin D deficiency may be an avoidable risk factor for syndrome ‘X', adding another preventative measure to current recommendations which are aimed at reducing the worldwide epidemic of these disorders. Experimentally, vitamin D deficiency progressively reduces insulin secretion; glucose intolerance follows and becomes irreversible. Relationships between vitamin D status, glucose tolerance and 30 min insulin secretion during oral glucose tolerance tests are reported in British Asians; insulin secretion, but not glycaemia, improving with short-term supplementation. Studies showing reduction in blood pressure and in risk of heart attack and diabetes with exercise (usually outdoor), rarely consider the role of vitamin D status. Glycaemia and insulin secretion in elderly European men, however, relate to vitamin D status, independent of season or physical activity. Prolonged supplementation can improve glycaemia. Hypertension improves with vitamin D treatment with or without initial deficiency. Vitamin D status and climate are reviewed as risk factors for myocardial infarction; the risk reducing with altitude despite increasing cold. Glycaemia and fibrinogenaemia improve and insulin secretion increases in summer. Variation in vitamin D requirements could arise from genetic differences in vitamin D processing since bone density can vary with vitamin D-receptor genotype. Vitamin D receptors are present in islet β cells and we report insulin secretion in healthy Asians differing profoundly with the Apa I genotype, being independent of vitamin D status. Those at risk of vitamin D deficiency include the elderly, those living indoors or having a covered-up style of dress, especially dark-skinned immigrants, and pregnant women, and these are groups recognized as being at increased risk of diabetes. Copyright © The Nutrition Society 1998 British Journal of Nutrition Cambridge University Press 79/4(1998-04), 315-327 0007-1145 79:4<315 1998 79 BJN https://doi.org/10.1079/BJN19980055 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1079/BJN19980055 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Boucher B. J. Academic Medical Unit and Cellular Mechanisms Research Group, St. Bartholomew's and the Royal London Hospital Medical & Dental School, Queen Mary Westfield, London El 1BB, UK NATIONALLICENCE 773 0- British Journal of Nutrition Cambridge University Press 79/4(1998-04), 315-327 0007-1145 79:4<315 1998 79 BJN CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence SWISSBIB 388062231 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge