Group items tagged

Long-term vitamin D3 supplementation may have adverse effects on serum lipids during postmenopausal hormone replacement therapy. Heikkinen AM, Tuppurainen MT, Niskanen L, Komulainen M, Penttilä I, Saarikoski S. Eur J Endocrinol. 1997 Nov;137(5):495-502. PMID: 9405029 CONCLUSIONS: Our results confirm the positive long-term effect of HRT with sequential estradiol valerate and cyproterone acetate on serum lipid concentrations. In addition, the results suggest that vitamin D3 supplementation may have unfavorable effects on lipids in postmenopausal women. Pure vitamin D3 treatment was associated with increased serum LDL cholesterol. Furthermore, the beneficial effects of HRT on serum LDL cholesterol content were reduced when estradiol valerate was combined with vitamin D3. However, the relevance of these associations to cardiovascular morbidity remains to be established.

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 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.

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 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.

Effect of four monthly oral vitamin D3 (cholecalciferol) supplementation on fractures and mortality in men and women living in the community: randomised double blind controlled trial. Trivedi DP, Doll R, Khaw KT. BMJ. 2003 Mar 1;326(7387):469. PMID: 12609940 CONCLUSION: Four monthly supplementation with 100 000 IU oral vitamin D may prevent fractures without adverse effects in men and women living in the general community.

The role of vitamin D in cancer prevention. Garland CF, Garland FC, Gorham ED, Lipkin M, Newmark H, Mohr SB, Holick MF. Am J Public Health. 2006 Feb;96(2):252-61. Epub 2005 Dec 27. Review. PMID: 16380576 DOI: 10.2105/AJPH.2004.045260 Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects

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

Prevalence and Associations of 25-Hydroxyvitamin D Deficiency in US Children: NHANES 2001-2004. Kumar J, Muntner P, Kaskel FJ, Hailpern SM, Melamed ML. Pediatrics. 2009 Aug 3. [Epub ahead of print] PMID: 19661054 CONCLUSIONS: 25(OH)D deficiency is common in the general US pediatric population and is associated with adverse cardiovascular risks.

Comment: The strengths of this randomized study include its high level of adherence and its use of a vitamin D dose sufficient to cause a biologically meaningful increase in serum levels. The adult daily value for vitamin D is 400 IU, but many U.S. women are vitamin-D-deficient (N Engl J Med 2007; 357:266). The Institute of Medicine considers doses up to 2000 IU to be without significant risk for adverse health effects. In addition to consuming dietary sources of vitamin D (see Table 1), most women will need supplements to achieve adequate intake. Multivitamins usually contain 400 IU of vitamin D.

The role of vitamin D in cancer prevention. Garland CF, Garland FC, Gorham ED, Lipkin M, Newmark H, Mohr SB, Holick MF. Am J Public Health. 2006 Feb;96(2):252-61. Epub 2005 Dec 27. Review. PMID: 16380576 DOI: 10.2105/AJPH.2004.045260 Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects.

Strong correlations have been noted between cardiovascular diseases and low bone density / osteoporosis-connections so strong that the presence of one is considered a likely predictor of the other. This relationship has led to the hypothesis that these conditions share core pathophysiological mechanisms. Recent advances in our understanding of the complimentary roles played by vitamin D3 and vitamin K2 in vascular and bone health provide support for this hypothesis, along with insight into key metabolic dysfunctions underlying cardiovascular disease and osteoporosis. Part II, The Vitamin K Connection to Cardiovascular Health, reviews the ways in which vitamin K regulates calcium utlization, preventing vascular and soft tissue calcification while complimenting the bone-building actions of vitamin D, and also discusses vitamin K safety and dosage issues, and the necessity of providing vitamin K and vitamin A along with vitamin D to preclude adverse effects associated with hypervitaminosis D.

Strong correlations have been noted between cardiovascular diseases and low bone density / osteoporosis-connections so strong that the presence of one type of pathology is considered a likely predictor of the other. This potentially causal relationship has led to the hypothesis that these conditions share core mechanisms. Recent advances in our understanding of the complimentary roles played by vitamin D3 and vitamin K2 in vascular and bone health provide support for this hypothesis, along with insight into key metabolic dysfunctions underlying cardiovascular disease and osteoporosis. Part I of this review summarizes current research linking vitamin D deficiency to cardiovascular disease, the physiological mechanisms underlying vitamin D's cardiovascular effects, and leading vitamin D researchers' recommendations for significantly higher supplemental doses of the pro-hormone. Part II reviews the vitamin K connection to cardiovascular disease; the ways in which vitamin D and vitamin K pair up to prevent inflammation, vascular calcification and osteoporosis; and the necessity of providing vitamin K along with vitamin D to preclude adverse effects associated with hypervitaminosis D, which include vascular and other soft tissue calcification.

Evidence from clinical trials shows, with a wide margin of confidence, that a prolonged intake of 10,000IU/d of vitamin D3 poses no risk of adverse effects for adults, even if this is added to a rather high physiologic background level of vitamin D. Vitamin D and cancer mini-symposium: the risk of additional vitamin D. Vieth R.\nAnn Epidemiol. 2009 Jul;19(7):441-5. Epub 2009 Apr 11. PMID: 19364661 doi:10.1016/j.annepidem.2009.01.009

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.

Vitamin D and cancer mini-symposium: the risk of additional vitamin D. Vieth R. Ann Epidemiol. 2009 Jul;19(7):441-5. Epub 2009 Apr 11. Review. PMID: 19364661 Conclusion The results of well-conducted trials of vitamin D lead to the conclusion that the current U.S. National Academy of Sciences-Institute of Medicine upper limit for vitamin D intake of 2000IU per day 1, 37 is excessively conservative. That intake would raise serum 25(OH)D by an average of about 50 nmol/L (20 ng/mL), well within the safe range of serum 25(OH)D concentrations that extends to 500 nmol/L (200 ng/mL). Intake of 4,000IU per day would raise serum 25(OH)D by an average of about 100 nmol/L (40 ng/mL). Even prolonged physiologic-replacement intake of 10,000IU per day of vitamin D3 would pose no known risk of adverse effects in virtually all adults.

Vitamin D Toxicity Fears Unwarranted Is vitamin D toxic? Not if we take the same amount nature intended when we go out in the sun. Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentration, and safety. Am J Clin Nutr. 1999;69:842-56. Vieth attempted to dispel unwarranted fears in medical community of physiological doses of vitamin D in 1999 with his exhaustive and well-written review. D-Lite, Renew, & SunSplash UV/Tanning Systems Sunsplash Tanning System Is toxicity a concern for you? If so, then increase your levels the way nature intended, with ultraviolet B light! His conclusions: fear of vitamin D toxicity is unwarranted, and such unwarranted fear, bordering on hysteria, is rampant in the medical profession. Vieth R, Chan PC, MacFarlane GD. Efficacy and safety of vitamin D3 intake exceeding the lowest observed adverse effect level. Am J Clin Nutr. 2001 Feb;73(2):288-94. Even Ian Monroe, the chair of the relevant IOM committee, wrote to the Journal to compliment Vieth's work and to promise his findings will be considered at the time of a future Institute of Medicine review. Munro I. Derivation of tolerable upper intake levels of nutrients. Letter, Am J Clin Nutr. 2001;74:865. That was more than two years ago.

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.

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.

Effect of four monthly oral vitamin D3 (cholecalciferol) supplementation on fractures and mortality in men and women living in the community: randomised double blind controlled trial. Trivedi DP, Doll R, Khaw KT. BMJ. 2003 Mar 1;326(7387):469. PMID: 12609940 Conclusion: Four monthly supplementation with 100 000 IU oral vitamin D may prevent fractures without adverse effects in men and women living in the general community.

Calcium and vitamin D intakes may be positively associated with brain lesions in depressed and nondepressed elders. Payne ME, Anderson JJ, Steffens DC. Nutr Res. 2008 May;28(5):285-92. PMID: 19083421 doi: 10.1016/j.nutres.2008.02.013 In conclusion, calcium and vitamin D consumption were associated with brain lesions in elderly subjects even after controlling for potentially explanatory variables. These associations may be due to vascular calcification or other mechanism. The possibility of adverse effects of high intakes of calcium and vitamin D needs to be further explored in longitudinal studies of elderly subjects.

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.