Group items tagged

Dose response to vitamin D supplementation among postmenopausal African American women. Talwar SA, Aloia JF, Pollack S, Yeh JK. Am J Clin Nutr. 2007 Dec;86(6):1657-62. PMID: 18065583

Effectiveness and safety of vitamin D in relation to bone health. Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, Atkinson S, Ward L, Moher D, Hanley D, Fang M, Yazdi F, Garritty C, Sampson M, Barrowman N, Tsertsvadze A, Mamaladze V. Evid Rep Technol Assess (Full Rep). 2007 Aug;(158):1-235. Review. PMID: 18088161

25-hydroxyvitamin D, IGF-1, and metabolic syndrome at 45 years of age: a cross-sectional study in the 1958 British Birth Cohort. Hyppönen E, Boucher BJ, Berry DJ, Power C. Diabetes. 2008 Feb;57(2):298-305. Epub 2007 Nov 14. PMID: 18003755 doi: 10.2337/db07-1122 CONCLUSIONS-Serum 25(OH)D is inversely associated with metabolic syndrome, whereas the inverse association with IGF-1 was found only among those without hypovitaminosis D. These results suggest that metabolic syndrome prevalence is the lowest when both 25(OH)D and IGF-1 are high.

Circulating 25-hydroxyvitamin d levels and survival in patients with colorectal cancer. Ng K, Meyerhardt JA, Wu K, Feskanich D, Hollis BW, Giovannucci EL, Fuchs CS. J Clin Oncol. 2008 Jun 20;26(18):2984-91. PMID: 18565885 DOI: 10.1200/JCO.2007.15.1027 Conclusion Among patients with colorectal cancer, higher prediagnosis plasma 25(OH)D levels were associated with a significant improvement in overall survival. Further study of the vitamin D pathway and its influence on colorectal carcinogenesis and cancer progression is warranted.

Severe vitamin D deficiency in Swiss hip fracture patients. Bischoff-Ferrari HA, Can U, Staehelin HB, Platz A, Henschkowski J, Michel BA, Dawson-Hughes B, Theiler R. Bone. 2008 Mar;42(3):597-602. Epub 2007 Nov 28. PMID: 18180211 BACKGROUND: Most clinical guidelines for the prevention of hip fractures recommend 800 IU vitamin D per day. This dose shifted serum 25-hydroxyvitamin D levels (25(OH)D) in previous studies to between 60 and 100 nmol/l. AIM: To measure 25(OH)D levels and prevalence of vitamin D supplementation in individuals age 65+ with acute hip fracture. METHODS: 222 consecutive hip fracture patients were investigated over a 12 month period. Mean age of patients was 86 years and 77% were women. RESULTS: Mean serum 25(OH)D levels were low among hip fracture patients admitted from home (34.6 nmol/l), from assisted living (27.7 nmol/l), and from nursing homes (24 nmol/l). Severe vitamin D deficiency below 30 nmol/l was present in 60%, 80% were below 50 nmol/l, and less than 4% reached desirable levels of at least 75 nmol/l. Consistently, only 10% of hip fracture patients had any vitamin D supplementation on admission to acute care with significantly higher 25(OH)D levels among individuals supplemented with 800-880 IU/day (63.5 nmol/l). Controlling for age and gender, vitamin D supplementation, type of dwelling, and season were independently and significantly associated with 25(OH)D levels. CONCLUSION: These data provide evidence that current guidelines for the prevention of hip fractures need further effort to be translated into clinical practice.

Vitamin D and skin physiology: a D-lightful story. Holick MF, Chen TC, Lu Z, Sauter E. J Bone Miner Res. 2007 Dec;22 Suppl 2:V28-33. PMID: 18290718 doi: 10.1359/jbmr.07s211 Very few foods naturally contain vitamin D, and those that do have a very variable vitamin D content. Recently it was observed that wild caught salmon had between 75% and 90% more vitamin D(3) compared with farmed salmon. The associations regarding increased risk of common deadly cancers, autoimmune diseases, infectious diseases, and cardiovascular disease with living at higher latitudes and being prone to vitamin D deficiency should alert all health care professionals about the importance of vitamin D for overall health and well being. Humans have depended on sunlight for their vitamin D requirement. The impact of season, time of day, and latitude on vitamin D synthesis is well documented.(2,3) We now report that altitude also has a dramatic influence on vitamin D3 production and that living at altitudes above 3500 m permits previtamin D3 production at a time when very little is produced at latitudes below 3400 m. It was surprising that, at 27° N in Agra (169 M), little previtamin D3 production was observed. However, there was significant air pollution that caused a haze over the city. It is likely the ozone and other UVB-absorbing pollutants in the air prevented the solar UVB photons from reaching the earth's surface to produce previtamin D3.

Childhood sun exposure influences risk of multiple sclerosis in monozygotic twins. Islam T, Gauderman WJ, Cozen W, Mack TM. Neurology. 2007 Jul 24;69(4):381-8. PMID: 17646631 Conclusion: Early sun avoidance seems to precede the diagnosis of multiple sclerosis (MS). This protective effect is independent of genetic susceptibility to MS.

Vitamin d and its role in cancer and immunity: a prescription for sunlight. Mullin GE, Dobs A. Nutr Clin Pract. 2007 Jun;22(3):305-22. Review. PMID: 17507731 DOI: 10.1177/0115426507022003305

Vitamin D may suppress infections which lead to development of Multiple Sclerosis Steven R Brenner, None (16 August 2007) J Neurol Neurosurg Psychiatry 2008 I read the article with reference to the inverse relationship between multiple sclerosis clinical activity and deficiency of vitamin D by Soilu-Hannienen (1) with interest, and was considering what mechanism could be in play to cause such a relationship. 25-hydroxylated metabolites of vitamin D act as intracellular regulators of the synthesis and action of defensin (2) molecules against bacterial antigens, defensin being an endogenously synthesized antimicrobial substance (2). Human cathelicidin antimicrobial peptide gene is a target of vitamin D receptor and is strongly up-regulated by 1,25-dihydroxyvitamin D3, indicating vitamin D receptor and the 1,25-dihydroxyvitaminD3 regulate primate innate immunity (3)

Conclusion The data point to a critical role for the VDR and 1,25(OH)2D3 in control of innate immunity and the response of the colon to chemical injury. Vitamin D and the vitamin D receptor are critical for control of the innate immune response to colonic injury. Froicu M, Cantorna MT. BMC Immunol. 2007 Mar 30;8:5. PMID: 17397543 doi:10.1186/1471-2172-8-5

Vitamin D supplementation. Eveleigh B. Can Fam Physician. 2007 Sep;53(9):1435; author reply 1435. PMID: 17872869 My concern regarding vitamin D2 is that it is a synthetic analogue and might interact with the vitamin D receptor differently in various cell systems. It has been reported that vitamin D3 might improve glycemic control.7 Vitamin D2 has been reported to cause worsening of glycemic control in people of East Indian descent.8 Is this because of vitamin D receptor polymorphism, or because of enhanced 24-hydroxylase enzyme activation, or is it due to how vitamin D2 interacts with the receptor? Until this has been sorted out, I feel safest using vitamin D3. There are about 2000 synthetic analogues of vitamin D. The search is on for one that can cross the blood-brain barrier to treat certain types of brain cancers without causing hypercalcemia.9 But then again, what other effects would this compound have? There are still so many unknowns

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.

Are sunlight deprivation and influenza epidemics associated with the onset of acute leukemia? Timonen T, Näyhä S, Koskela T, Pukkala E. Haematologica. 2007 Nov;92(11):1553-6. PMID: 18024404 doi:10.3324/haematol.10799 Month of diagnosis of 7,423 cases of acute leukemia (AL) in Finland during 1964-2003 were linked with data on influenza and solar radiation. Acute myeloblastic leukemia (AML) showed the highest risk in the dark season. During the light season, the incidence decreased by 58% (95% confidence interval, 16-79%) per 1,000 kJ/m2/d increase of solar radiation. Independent of solar radiation, AML increased by 9% (95% confidence interval, 0-19%) during influenza epidemics. Reoccurring at the same time annually, darkness-related vitamin D deficiency and influenza could cause successive and co-operative mutations leading to AL with a short latency.

Vitamin D toxicity, policy, and science. Vieth R. J Bone Miner Res. 2007 Dec;22 Suppl 2:V64-8. Review. PMID: 18290725 doi: 10.1359/jbmr.07s221

Vitamin D and skin physiology: a D-lightful story.\nHolick MF, Chen TC, Lu Z, Sauter E.\nJ Bone Miner Res. 2007 Dec;22 Suppl 2:V28-33.\nPMID: 18290718 \ndoi: 10.1359/jbmr.07s211\n

Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Am J Clin Nutr. 2007 Jun;85(6):1586-91. Erratum in: Am J Clin Nutr. 2008 Mar;87(3):794. PMID: 17556697 Conclusions: Improving calcium and vitamin D nutritional status substantially reduces all-cancer risk in postmenopausal women.

Genetic and non-genetic correlates of vitamins K and D.\nShea MK, Benjamin EJ, Dupuis J, Massaro JM, Jacques PF, D'Agostino RB Sr, Ordovas JM, O'Donnell CJ, Dawson-Hughes B, Vasan RS, Booth SL.\nEur J Clin Nutr. 2007 Nov 21. [Epub ahead of print]\nPMID: 18030310 \ndoi: 10.1038/sj.ejcn\n\n

Reginster JY. Prevalence of vitamin D inadequacy in European postmenopausal women. Curr Med Res Opin. 2007 Jul 12; [Epub ahead of print] PMID: 17631697 [PubMed - as supplied by publisher]

Gonzalez G, Alvarado JN, Rojas A, Navarrete C, Velasquez CG, Arteaga E. High prevalence of vitamin D deficiency in Chilean healthy postmenopausal women with normal sun exposure: additional evidence for a worldwide concern. Menopause. 2007 May-Jun;14(3

Gorham ED, Garland CF, Garland FC, Grant WB, Mohr SB, Lipkin M, Newmark HL, Giovannucci E, Wei M, Holick MF. Optimal vitamin D status for colorectal cancer prevention: a quantitative meta analysis. Am J Prev Med. 2007 Mar;32(3):210-6. PMID: 17296473