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.
The role of vitamin D and calcium in type 2 diabetes. A systematic review and meta-analysis.
Pittas AG, Lau J, Hu FB, Dawson-Hughes B.
J Clin Endocrinol Metab. 2007 Jun;92(6):2017-29. Epub 2007 Mar 27. Review.
PMID: 17389701
.CONCLUSIONS: Vitamin D and calcium insufficiency may negatively influence glycemia, whereas combined supplementation with both nutrients may be beneficial in optimizing glucose metabolism.
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 and diabetes: improvement of glycemic control with vitamin D3 repletion.
Schwalfenberg G.
Can Fam Physician. 2008 Jun;54(6):864-6.
PMID: 18556494
Conclusion
These cases support information that is already known about VTD and its effect on the islet cell. As discussed above, this might be true only for vitamin D3 and not vitamin D2, although vitamin D2 has been shown to improve bone health. Vitamin D insufficiency or deficiency is common, and repletion might improve glycemic control early in type 2 diabetes. Diabetes is one of the fastest growing chronic diseases worldwide. Vitamin D3 is inexpensive and readily available. Well-designed clinical studies are required to ascertain if improving 25(OH)D levels from an insufficiency or deficiency to sufficiency improves glycemic control in diabetes. These studies need to be properly designed: a randomized controlled trial with VTD deficiency or insufficiency identified in diabetic patients of various ethnic
Comparison of daily, weekly, and monthly vitamin D3 in ethanol dosing protocols for two months in elderly hip fracture patients.
Ish-Shalom S, Segal E, Salganik T, Raz B, Bromberg IL, Vieth R.
J Clin Endocrinol Metab. 2008 Sep;93(9):3430-5. Epub 2008 Jun 10.
PMID: 18544622
doi:10.1210/jc.2008-0241
CONCLUSIONS: Supplementation with vitamin D can be achieved equally well with daily, weekly, or monthly dosing frequencies. Therefore, the choice of dose frequency can be based on whichever approach will optimize an individual's adherence with long-term vitamin D supplementation.
25-hydroxyvitamin D levels inversely associate with risk for developing coronary artery calcification.
de Boer IH, Kestenbaum B, Shoben AB, Michos ED, Sarnak MJ, Siscovick DS.
J Am Soc Nephrol. 2009 Aug;20(8):1805-12. Epub 2009 May 14.
PMID: 19443637
doi: 10.1681/ASN.2008111157
"In conclusion, lower 25-hydroxyvitamin D concentrations associate with increased risk for incident CAC. Accelerated development of atherosclerosis may underlie, in part, the increased cardiovascular risk associated with vitamin D deficiency."
Effect of vitamin D deficiency and replacement on endothelial function in asymptomatic subjects.
Tarcin O, Yavuz DG, Ozben B, Telli A, Velioglu Ogunc A, Yuksel M, Toprak A, Yazici D, Sancak S, Deyneli O, Akalin S.
J Clin Endocrinol Metab. 2009 Jul 7. [Epub ahead of print]
PMID: 19584181
doi:10.1210/jc.2008-1212
Conclusions: This study shows that 25(OH)D deficiency is associated with endothelial dysfunction and increased lipid peroxidation. Replacement of vitamin D has favorable effects on endothelial function. Vitamin D deficiency can be seen as an independent risk factor of atherosclerosis. Hypovitaminosis D associated endothelial dysfunction may predispose to higher cardiovascular disease in the winter.
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.
Estimation of the dietary requirement for vitamin D in free-living adults >=64 y of age.
Cashman KD, Wallace JM, Horigan G, Hill TR, Barnes MS, Lucey AJ, Bonham MP, Taylor N, Duffy EM, Seamans K, Muldowney S, Fitzgerald AP, Flynn A, Strain JJ, Kiely M.
Am J Clin Nutr. 2009 May;89(5):1366-74. Epub 2009 Mar 18.
PMID: 19297462
doi:10.3945/ajcn.2008.27334
Conclusion: To ensure that the vitamin D requirement is met by the vast majority (>97.5%) of adults aged ≥64 y during winter, between 7.9 and 42.8 µg vitamin D/d is required, depending on summer sun exposure and the threshold of adequacy of 25(OH)D. .
Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration.
Aloia JF, Patel M, Dimaano R, Li-Ng M, Talwar SA, Mikhail M, Pollack S, Yeh JK.
Am J Clin Nutr. 2008 Jun;87(6):1952-8.
PMID: 18541590
The mean daily dose was 86 microg (3440 IU). The use of computer simulations to obtain the most participants within the range of 75-220 nmol/L predicted an optimal daily dose of 115 microg/d (4600 IU). No hypercalcemia or hypercalciuria was observed. CONCLUSIONS: Determination of the intake required to attain serum 25(OH)D concentrations >75 nmol/L must consider the wide variability in the dose-response curve and basal 25(OH)D concentrations. Projection of the dose-response curves observed in this convenience sample onto the population of the third National Health and Nutrition Examination Survey suggests a dose of 95 microg/d (3800 IU) for those above a 25(OH)D threshold of 55 nmol/L and a dose of 125 microg/d (5000 IU) for those below that threshold.
How much vitamin D3 do the elderly need?
Viljakainen HT, Palssa A, Kärkkäinen M, Jakobsen J, Lamberg-Allardt C.
J Am Coll Nutr. 2006 Oct;25(5):429-35.
PMID: 17031013
Conclusions: A clear dose response was noted in S-25-OHD to different doses of vitamin D3. The recommended dietary intake of 15 µg is adequate to maintain the S-25-OHD concentration around 40-55 nmol/L during winter, but if the optimal S-25-OHD is higher than that even higher vitamin D intakes are needed. Interestingly, subjects with lower vitamin D status at baseline responded more efficiently to supplementation than those with more adequate status
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.
Vitamin D status in apparently healthy adults in Kashmir Valley of Indian subcontinent.
Zargar AH, Ahmad S, Masoodi SR, Wani AI, Bashir MI, Laway BA, Shah ZA.
Postgrad Med J. 2007 Nov;83(985):713-6.
PMID: 17989271
doi:10.1136/pgmj.2007.059113
Conclusions: In spite of abundant sunlight, healthy individuals in Kashmir valley are vitamin D deficient, particularly women. Serum 25 (OH) D concentrations are significantly related to sun exposure
Prevalence of Vitamin D inadequacy among postmenopausal North American women receiving osteoporosis therapy.
Holick MF, Siris ES, Binkley N, Beard MK, Khan A, Katzer JT, Petruschke RA, Chen E, de Papp AE.
J Clin Endocrinol Metab. 2005 Jun;90(6):3215-24. Epub 2005 Mar 29.
PMID: 15797954
doi:10.1210/jc.2004-2364
Conclusions: More than half of North American women receiving therapy to treat or prevent osteoporosis have vitamin D inadequacy, underscoring the need for improved physician and public education regarding optimization of vitamin D status in this population.
Age-related changes in the 25-hydroxyvitamin D versus parathyroid hormone relationship suggest a different reason why older adults require more vitamin D.
Vieth R, Ladak Y, Walfish PG.
J Clin Endocrinol Metab. 2003 Jan;88(1):185-91.
PMID: 12519850
This study shows that all age groups exhibit a high prevalence of 25(OH)D insufficiency and secondary hyperparathyroidism. Older adults are just as efficient in maintaining 25(OH)D, but they need more vitamin D to produce the higher 25(OH)D concentrations required to overcome the hyperparathyroidism associated with their diminishing renal function
Matsuoka, L. Y., Wortsman, J., Hanifan, N. & Holick, M. F. (1988)
Chronic sunscreen use decreases circulating concentrations of 25-hydroxyvitamin D: a preliminary study.
Arch. Dermatol. 124:1802-1804
Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials.
Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B.
JAMA. 2005 May 11;293(18):2257-64. Review.
PMID: 15886381
Conclusions Oral vitamin D supplementation between 700 to 800 IU/d appears to reduce the risk of hip and any nonvertebral fractures in ambulatory or institutionalized elderly persons. An oral vitamin D dose of 400 IU/d is not sufficient for fracture prevention.
Dietary recommendations for vitamin D: a critical need for functional end points to establish an estimated average requirement.
Whiting SJ, Calvo MS.
J Nutr. 2005 Feb;135(2):304-9. Review.
PMID: 15671232
In summary, vitamin D has emerged as a critical nutrient for which there is a compelling health need to establish adequate dietary guidelines in North America and worldwide given the increasing evidence of vitamin D deficiency and insufficient links to risk of chronic disease. We strongly argue that now there are enough data to consider setting an estimated average requirement for vitamin D and to recognize the crucial need for more research to determine the role of vitamin D in noncalciotropic functions and prevention of chronic diseases
