Group items tagged

Supplementation with cholecalciferol does not improve glycaemic control in diabetic subjects with normal serum 25-hydroxyvitamin D levels. Jorde R, Figenschau Y. Eur J Nutr. 2009 Apr 16. [Epub ahead of print] PMID: 19370371 10.1007/s00394-009-0020-3 Conclusions We were not able to demonstrate that vitamin D supplementation had a significant effect on glucose metabolism in subjects with type 2 diabetes but without vitamin D deficiency. Further studies are needed in larger groups of subjects with type 2 diabetes or impaired glucose tolerance, who also exhibit low serum 25-hydroxyvitamin D levels.

Serum 25-hydroxyvitamin D levels and the prevalence of peripheral arterial disease: results from NHANES 2001 to 2004. Melamed ML, Muntner P, Michos ED, Uribarri J, Weber C, Sharma J, Raggi P. Arterioscler Thromb Vasc Biol. 2008 Jun;28(6):1179-85. Epub 2008 Apr 16. PMID: 18417640 doi: 10.1161/ATVBAHA.108.165886 Conclusions- Low serum 25(OH)D levels are associated with a higher prevalence of PAD. Several mechanisms have been invoked in the literature to support a potential antiatherosclerotic activity of vitamin D. Prospective cohort and mechanistic studies should be designed to confirm this association. Vitamin D is an inhibitor of the renin-angiotensin system and has antiinflammatory and anticoagulant properties. Among 4839 NHANES 2001 to 2004 participants, low 25(OH)D levels were associated with a higher prevalence of PAD, after multivariate adjustment. To confirm this association, longitudinal cohort and mechanistic studies are needed.

Serum 25-hydroxyvitamin D3 concentrations and carotid artery intima-media thickness among type 2 diabetic patients. Targher G, Bertolini L, Padovani R, Zenari L, Scala L, Cigolini M, Arcaro G. Clin Endocrinol (Oxf). 2006 Nov;65(5):593-7. PMID: 17054459 DOI: 10.1111/j.1365-2265.2006.02633.x CONCLUSIONS: Hypovitaminosis D is highly prevalent in type 2 diabetic adults and is strongly and independently associated with increased carotid IMT. Further investigation into whether vitamin D may play a role in the prevention of atherosclerosis appears to be warranted. In conclusion, our results show that type 2 diabetic adults have significant reductions in serum 25(OH)D concentrations (vs matched controls) that predict preclinical atherosclerosis, independent of classical risk factors, renal function tests, inflammatory markers, use of medications and presence of the metabolic syndrome. These findings suggest the need for ongoing evaluation of the possible protective role of vitamin D3 supplementation in the development of atherosclerosis.

Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Ginde AA, Mansbach JM, Camargo CA Jr. Arch Intern Med. 2009 Feb 23;169(4):384-90. PMID: 19237723 Conclusions Serum 25(OH)D levels are inversely associated with recent URTI. This association may be stronger in those with respiratory tract diseases. Randomized controlled trials are warranted to explore the effects of vitamin D supplementation on RTI.

Meta-analysis: longitudinal studies of serum vitamin D and colorectal cancer risk. Yin L, Grandi N, Raum E, Haug U, Arndt V, Brenner H. Aliment Pharmacol Ther. 2009 Jul 1;30(2):113-25. Epub 2009 Apr 15. PMID: 19392870 DOI: 10.1111/j.1365-2036.2009.04022.x Conclusions Our results support suggestions that serum 25(OH)D is inversely related to CRC risk.

Prospective Study of Serum 25-Hydroxyvitamin D Level, Cardiovascular Disease Mortality, and All-Cause Mortality in Older U.S. Adults. Ginde AA, Scragg R, Schwartz RS, Camargo CA Jr. J Am Geriatr Soc. 2009 Jun 22. [Epub ahead of print] PMID: 19549021 DOI: 10.1111/j.1532-5415.2009.02359.x CONCLUSION: In noninstitutionalized older adults, a group at high risk for all-cause mortality, serum 25(OH)D levels had an independent, inverse association with CVD and all-cause mortality. Randomized controlled trials of vitamin D supplementation in older adults are warranted to determine whether this association is causal and reversible.

25(OH)D Serum levels decline with age earlier in women than in men and less efficiently prevent compensatory hyperparathyroidism in older adults. Maggio D, Cherubini A, Lauretani F, Russo RC, Bartali B, Pierandrei M, Ruggiero C, Macchiarulo MC, Giorgino R, Minisola S, Ferrucci L. J Gerontol A Biol Sci Med Sci. 2005 Nov;60(11):1414-9. PMID: 16339327 Conclusions. These findings suggest that the age-associated fall of serum 25(OH)D starts earlier in women than in men and that higher levels of 25(OH)D are required in older compared to younger persons to avoid the age-associated compensatory hyperparathyroidism.

March 27, 2009 - A significant decrease in serum 25-hydroxyvitamin D (25[OH]D) levels has led to an increase in vitamin D insufficiency in the US population, especially in racial and ethnic groups, according to results of a population-based study reported in the March 23 issue of the Archives of Internal Medicine. "Vitamin D insufficiency has been associated with increases in cardiovascular disease, cancer, and infection," write Adit A. Ginde, MD, from the Department of Emergency Medicine at the University of Colorado Denver School of Medicine, Aurora, Colorado, and colleagues. "Vitamin D supplementation appears to mitigate the incidence and adverse outcomes of these diseases and may reduce all-cause mortality." [...] "These findings have important implications for health disparities and public health," the study authors conclude. "Our data provide additional evidence that current recommendations for vitamin D supplementation (200-600 IU/d) are inadequate to achieve optimal serum 25(OH)D levels in most of the US population." They add that large, randomized controlled trials of higher doses of vitamin D supplementation are needed to evaluate their effect on general health and mortality.

Conclusions: Healthy men seem to use 3000-5000 IU cholecalciferol/d, apparently meeting > 80% of their winter cholecalciferol need with cutaneously synthesized accumulations from solar sources during the preceding summer months. Current recommended vitamin D inputs are inadequate to maintain serum 25-hydroxycholecalciferol concentration in the absence of substantial cutaneous production of vitamin D. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Am J Clin Nutr. 2003 Jan;77(1):204-10. Erratum in: Am J Clin Nutr. 2003 Nov;78(5):1047. PMID: 12499343

Low vitamin D serum level is related to severe fibrosis and low responsiveness to IFN-based therapy in genotype 1 chronic hepatitis C Salvatore Petta et al. Hepatology, Volume 9999 Issue 999A, Page NA. Published Online: 4 Dec 2009 DOI: 10.1002/hep.23489 Conclusions: G1 CHC patients had low 25(OH)D serum levels, possibly due to reduced CYP27A1 expression. Low vitamin D is linked to severe fibrosis and low SVR on IFN-based therapy. (HEPATOLOGY 2010.)

Serum vitamin D concentration and prostate cancer risk: a nested case-control study. Ahn J, Peters U, Albanes D, Purdue MP, Abnet CC, Chatterjee N, Horst RL, Hollis BW, Huang WY, Shikany JM, Hayes RB; Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Project Team. J Natl Cancer Inst. 2008 Jun 4;100(11):796-804. Epub 2008 May 27. PMID: 18505967 doi:10.1093/jnci/djn152 CONCLUSION: The findings of this large prospective study do not support the hypothesis that vitamin D is associated with decreased risk of prostate cancer; indeed, higher circulating 25(OH)D concentrations may be associated with increased risk of aggressive disease. In summary, results from this large prospective study of men who underwent standardized prostate cancer screening in the context of a screening trial do not support the hypothesis that higher serum vitamin D status is associated with decreased risk of prostate cancer. The study showed no association of vitamin D level with nonaggressive disease; however, it raises the possibility that higher vitamin D level may be associated with increased risks for aggressive disease, although a clear monotonic dose-response relationship was lacking. Along with recent reports of adverse associations for higher vitamin D status and risk of pancreatic (32) and esophageal (33,34) cancer, caution should be taken in recommending high doses of vitamin D or sunlight exposure to the general public for prostate cancer prevention. Future analyses are warranted to confirm these results and to further clarify the effects of vitamin D on aggressive prostate cancer.

Meta-analysis of longitudinal studies: Serum vitamin D and prostate cancer risk. Yin L, Raum E, Haug U, Arndt V, Brenner H. Cancer Epidemiol. 2009 Dec;33(6):435-45. Epub 2009 Nov 25. PMID: 19939760 doi:10.1016/j.canep.2009.10.014 CONCLUSIONS: According to available evidence from longitudinal studies, serum 25(OH)D is not associated with PC incidence.

Plasma calcidiol, season, and serum parathyroid hormone concentrations in healthy elderly men and women. Dawson-Hughes B, Harris SS, Dallal GE. Am J Clin Nutr. 1997 Jan;65(1):67-71. PMID: 8988915 Plasma calcidiol and serum PTH concentrations were inversely related, with PTH rising slowly as calcidiol concentrations declined below 110 nmol/L (95 CI: 60, 168 nmol/L). More than 90% of the men and women had calcidiol concentrations below this value in the wintertime. The high prevalence of lower wintertime calcidiol values may increase risk of bone loss in elderly men and women.

Serum 25-Hydroxyvitamin D Levels Among US Children Aged 1 to 11 Years: Do Children Need More Vitamin D? Mansbach JM, Ginde AA, Camargo CA Jr. Pediatrics. 2009 Nov;124(5):1404-1410. PMID: 19951983 CONCLUSIONS: On the basis of a nationally representative sample of US children aged 1 to 11 years, millions of children may have suboptimal levels of 25(OH)D, especially non-Hispanic black and Hispanic children. More data in children are needed not only to understand better the health implications of specific serum levels of 25(OH)D but also to determine the appropriate vitamin D supplement requirements for children.

25-Hydroxyvitamin D and functional outcomes in adolescents. Lamberg-Allardt CJ, Viljakainen HT. Am J Clin Nutr. 2008 Aug;88(2):534S-536S. Review. PMID: 18689396 CONCLUSIONS Cross-sectional studies have shown a relation among serum 25(OH)D concentration, serum PTH concentration, and BMD in adolescents. Long-term randomized controlled intervention studies have shown that vitamin D3 supplementation has a positive effect on BMD in adolescence; some of these studies found an effect with doses as small as 5 µg (200 IU) to 10 µg (400 IU) per day, or without supplemental calcium.

Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D. Holick MF, Biancuzzo RM, Chen TC, Klein EK, Young A, Bibuld D, Reitz R, Salameh W, Ameri A, Tannenbaum AD. J Clin Endocrinol Metab. 2008 Mar;93(3):677-81. Epub 2007 Dec 18. PMID: 18089691 Conclusion: A 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.

Vitamin D status predicts physical performance and its decline in older persons. Wicherts IS, van Schoor NM, Boeke AJ, Visser M, Deeg DJ, Smit J, Knol DL, Lips P. J Clin Endocrinol Metab. 2007 Jun;92(6):2058-65. Epub 2007 Mar 6. PMID: 17341569 doi:10.1210/jc.2006-1525 ONCLUSIONS: Serum 25-OHD concentrations below 20 ng/ml are associated with poorer physical performance and a greater decline in physical performance in older men and women. Because almost 50% of the population had serum 25-OHD below 20 ng/ml, public health strategies should be aimed at this group.

Vitamin D in preventive medicine: are we ignoring the evidence? Zittermann A. Br J Nutr. 2003 May;89(5):552-72. Review. PMID: 12720576 Vitamin D is metabolised by a hepatic 25-hydroxylase into 25-hydroxyvitamin D (25(OH)D) and by a renal 1alpha-hydroxylase into the vitamin D hormone calcitriol. Calcitriol receptors are present in more than thirty different tissues. Apart from the kidney, several tissues also possess the enzyme 1alpha-hydroxylase, which is able to use circulating 25(OH)D as a substrate. Serum levels of 25(OH)D are the best indicator to assess vitamin D deficiency, insufficiency, hypovitaminosis, adequacy, and toxicity. European children and young adults often have circulating 25(OH)D levels in the insufficiency range during wintertime. Elderly subjects have mean 25(OH)D levels in the insufficiency range throughout the year. In institutionalized subjects 25(OH)D levels are often in the deficiency range. There is now general agreement that a low vitamin D status is involved in the pathogenesis of osteoporosis. Moreover, vitamin D insufficiency can lead to a disturbed muscle function. Epidemiological data also indicate a low vitamin D status in tuberculosis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases, hypertension, and specific types of cancer. Some intervention trials have demonstrated that supplementation with vitamin D or its metabolites is able: (i) to reduce blood pressure in hypertensive patients; (ii) to improve blood glucose levels in diabetics; (iii) to improve symptoms of rheumatoid arthritis and multiple sclerosis. The oral dose necessary to achieve adequate serum 25(OH)D levels is probably much higher than the current recommendations of 5-15 microg/d.

Serum 25-hydroxyvitamin D status of vegetarians, partial vegetarians, and nonvegetarians: the Adventist Health Study-2. Chan J, Jaceldo-Siegl K, Fraser GE. Am J Clin Nutr. 2009 May;89(5):1686S-1692S. Epub 2009 Apr 1. PMID: 19339396 Conclusions: s25(OH)D concentrations were not associated with vegetarian status. Other factors, such as vitamin D supplementation, degree of skin pigmentation, and amount and intensity of sun exposure have greater influence on s25(OH)D than does diet.

Summary of evidence-based review on vitamin D efficacy and safety in relation to bone health. Cranney A, Weiler HA, O'Donnell S, Puil L. Am J Clin Nutr. 2008 Aug;88(2):513S-519S. Review. PMID: 18689393 We found inconsistent evidence of an association between serum 25-hydroxyvitamin D [25(OH)D] concentration and bone mineral content in infants and fair evidence of an association with bone mineral content or density in older children and older adults. The evidence of an association between serum 25(OH)D concentration and some clinical outcomes (fractures, performance measures) in postmenopausal women and older men was inconsistent, and the evidence of an association with falls was fair. We found good evidence of a positive effect of consuming vitamin D-fortified foods on 25(OH)D concentrations. The evidence for a benefit of vitamin D on falls and fractures varied. We found fair evidence that adults tolerated vitamin D at doses above current dietary reference intake levels, but we had no data on the association between long-term harms and higher doses of vitamin D.