Group items tagged

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.

Evolution and function of vitamin D. Holick MF. Recent Results Cancer Res. 2003;164:3-28. Review. PMID: 12899511

Vitamin D status: measurement, interpretation, and clinical application. Holick MF. Ann Epidemiol. 2009 Feb;19(2):73-8. Epub 2008 Mar 10. Review. PMID: 18329892 Conclusion The only way to determine whether a person is vitamin D deficient or sufficient is to measure their circulating level of 25(OH)D. There are a variety of assays used to measure 25(OH)D. The radioimmunoassays and competitive protein binding assays for 25(OH)D are useful in detecting vitamin D deficiency and sufficiency. However, these assays are fraught with technical difficulties, especially if they are not run routinely (Fig. 4) (33). Several reference laboratories have now switched to LC-MS ,which measures both 25(OH)D2 and 25(OH)D3 quantitatively. The total 25(OH)D, i.e., 25(OH)D2 plus 25(OH)D3, is what physicians need to be aware of for their patients. A level >30 ng/mL is

A seasonal variation of calcitropic hormones, bone turnover and bone mineral density in early and mid-puberty girls - a cross-sectional study. Viljakainen HT, Palssa A, Kärkkäinen M, Jakobsen J, Cashman KD, Mølgaard C, Lamberg-Allardt C. Br J Nutr. 2006 Jul;96(1):124-30. PMID: 16870000 Seasonal variation in S-25-OHD and bone remodelling markers accompanied by negative correlation between S-25-OHD and S-iPTH was seen in this cross-sectional study of adolescent girls. In addition, the seasonal rhythm contributed 7.0-7.6 % difference in the BMD of lumbar vertebrae and left femur in early puberty girls. This variation should be avoided since it could hamper peak bone mass attainment.

Sunlight and vitamin D: both good for cardiovascular health. Holick MF. J Gen Intern Med. 2002 Sep;17(9):733-5. PMID: 12220371 doi: 10.1046/j.1525-1497.2002.20731.x.

Vitamin D and disease prevention with special reference to cardiovascular disease. Zittermann A. Prog Biophys Mol Biol. 2006 Sep;92(1):39-48. Epub 2006 Feb 28. Review. PMID: 1660034

Association of low 25-hydroxyvitamin D concentrations with elevated parathyroid hormone concentrations and low cortical bone density in early pubertal and prepubertal Finnish girls. Cheng S, Tylavsky F, Kröger H, Kärkkäinen M, Lyytikäinen A, Koistinen A, Mahonen A, Alen M, Halleen J, Väänänen K, Lamberg-Allardt C. Am J Clin Nutr. 2003 Sep;78(3):485-92. Erratum in: Am J Clin Nutr. 2006 Jan;83(1):174. PMID: 12936933 CONCLUSIONS: Vitamin D-deficient girls have low cortical BMD and high iPTH concentrations, which are consistent with secondary hyperparathyroidism. A low vitamin D concentration accompanied by high bone resorption (TRAP 5b) may limit the accretion of bone mass in young girls.

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.

A longitudinal study of serum 25-hydroxyvitamin D and intact parathyroid hormone levels indicate the importance of vitamin D and calcium homeostasis regulation in multiple sclerosis. Soilu-Hänninen M, Laaksonen M, Laitinen I, Erälinna JP, Lilius EM, Mononen I. J Neurol Neurosurg Psychiatry. 2008 Feb;79(2):152-7. Epub 2007 Jun 19. PMID: 17578859 doi:10.1136/jnnp.2006.105320 Conclusions: The endocrine circuitry regulating serum calcium may be altered in MS. There is an inverse relationship between serum vitamin D level and MS clinical activity. The role of vitamin D in MS must be explored further.

Clinical Responses to a Mega-dose of Vitamin D3 in Infants and Toddlers With Vitamin D Deficiency Rickets. Soliman AT, El-Dabbagh M, Adel A, Ali MA, Aziz Bedair EM, Elalaily RK. J Trop Pediatr. 2009 Jun 8. [Epub ahead of print] PMID: 19506025 doi:10.1093/tropej/fmp040 Conclusion: An IM injection of a mega dose of cholecalciferol is a safe and effective therapy for treatment of VDD rickets in infants and toddlers with normalization of all the biochemical parameters and healing of radiological manifestations. Measurement of serum 25(OH)D level is highly recommended in all short children with a clear need for a general vitamin D supplementation for all infants and young children in Qatar.

Low vitamin D status despite abundant sun exposure. Binkley N, Novotny R, Krueger D, Kawahara T, Daida YG, Lensmeyer G, Hollis BW, Drezner MK. J Clin Endocrinol Metab. 2007 Jun;92(6):2130-5. Epub 2007 Apr 10. PMID: 17426097 doi:10.1210/jc.2006-2250 CONCLUSIONS: These data suggest that variable responsiveness to UVB radiation is evident among individuals, causing some to have low vitamin D status despite abundant sun exposure. In addition, because the maximal 25(OH)D concentration produced by natural UV exposure appears to be approximately 60 ng/ml, it seems prudent to use this value as an upper limit when prescribing vitamin D supplementation.

Vitamin D supplementation enhances the beneficial effects of weight loss on cardiovascular disease risk markers. Zittermann A, Frisch S, Berthold HK, Götting C, Kuhn J, Kleesiek K, Stehle P, Koertke H, Koerfer R. Am J Clin Nutr. 2009 May;89(5):1321-7. Epub 2009 Mar 25. PMID: 19321573

Using these functional indicators, several studies have more accurately defined vitamin D deficiency as circulating levels of 25(OH)D ≤ 80 nmol or 32 µg/L. Recent studies reveal that current dietary recommendations for adults are not sufficient to maintain circulating 25(OH)D levels at or above this level, especially in pregnancy and lactation. Circulating 25-hydroxyvitamin D levels indicative of vitamin D sufficiency: implications for establishing a new effective dietary intake recommendation for vitamin D. Hollis BW. J Nutr. 2005 Feb;135(2):317-22. Review. PMID: 15671234 [

Acid-base balance has an effect on bone turnover, especially on the rates of bone resorption and calcium mobilization. Bone mineral participates in the defense against acid-base disturbances, especially against metabolic acidosis (Lemann et al. 1966, Green & Kleeman 1991). The role of the bone mineral is important in the acid-base disorders, as no appreciable change in the intestinal calcium absorption occurs (Bichara et al. 1990). In the mammalian body, mainly three hormones regulate the calcium metabolism and the bone turnover. 1,25-dihydroxycholecalciferol (vitamin D derivative) increases calcium absorption from the intestine and, indirectly, from bone. Parathyroid hormone mobilizes calcium from the bone and increases the urinary phosphate excretion. Calcitonin inhibits bone resorption (Ganong 1981). Used as drugs, these hormones are also capable of inducing acid-base disorders. Calcitonin administration (Escanero et al. 1991) and vitamin D excess (Bichara et al. 1990) have been reported to cause metabolic alkalosis.

Low serum 25-hydroxyvitamin D concentrations and secondary hyperparathyroidism in middle-aged white strict vegetarians. Lamberg-Allardt C, Kärkkäinen M, Seppänen R, Biström H. Am J Clin Nutr. 1993 Nov;58(5):684-9. PMID: 8237875 In conclusion, white strict vegetarians are at risk of vitamin D deficiency, at least in the winter, primarily because of a low dietary vitamin D intake, despite a normal sunlight exposure in summer. Low serum 25(OH)D concentrations are accompanied by high S-iPTH concentrations, which also are affected by a low calcium intake. The effect of these changes on bone health remains to be evaluated.

Vitamin D status affects serum parathyroid hormone concentrations during winter in female adolescents: associations with forearm bone mineral density. Outila TA, Kärkkäinen MU, Lamberg-Allardt CJ. Am J Clin Nutr. 2001 Aug;74(2):206-10. PMID: 11470722 Conclusion: A large percentage of adolescent females have low vitamin D status during the winter in Finland, which seems to have negative effects on bone health.

A high prevalence of hypovitaminosis D in Finnish medical in- and outpatients. Kauppinen-Mäkelin R, Tähtelä R, Löyttyniemi E, Kärkkäinen J, Välimäki MJ. J Intern Med. 2001 Jun;249(6):559-63. PMID: 11422663 DOI: 10.1046/j.1365-2796.2001.00847.x CONCLUSION: Hypovitaminosis D is very common amongst Finnish in- and outpatients in both sexes, causing secondary hyperparathyroidism in females. More extensive studies are warranted to elucidate the vitamin D status of the Finnish population.

Vitamin D deficiency and bone health in healthy adults in Finland: could this be a concern in other parts of Europe? Lamberg-Allardt CJ, Outila TA, Kärkkainen MU, Rita HJ, Valsta LM. J Bone Miner Res. 2001 Nov;16(11):2066-73. PMID: 11697803 Low vitamin D status was prevalent in these young adults in northern Europe in winter, although the vitamin D intake met the recommendation. This probably is not a local problem for northern Europe, because the natural sources of vitamin D are scarce and fortification is not very common in Europe, and with the exception of the southern part of Europe, sunshine is not very abundant in this part of the world. Thus, the results of this study indicate that more attention should be focused on vitamin D status and the sources of vitamin D in these countries.

Unusually prolonged vitamin D intoxication after discontinuation of vitamin D: possible role of primary hyperparathyroidism. Taskapan H, Vieth R, Oreopoulos DG. Int Urol Nephrol. 2008;40(3):801-5. Epub 2008 Jun 5. PMID: 18528779 DOI: 10.1007/s11255-008-9404-1

Calcium absorption varies within the reference range for serum 25-hydroxyvitamin D. Heaney RP, Dowell MS, Hale CA, Bendich A. J Am Coll Nutr. 2003 Apr;22(2):142-6. PMID: 12672710