Men's Osteoporosis Support GroupVitamin D3 update A recent Update discussed the use of supplementing with vitamin D2 versus D3, with the conclusion that D3 was much more potent. It, however, was not available yet in the U.S. That is no longer the case since high-potency vitamin D3 can now be purchased either online or in stores. Just do an online search for "vitamin D3" to check the availability, pricing and dosages you can buy or have prescribed. Vitamin D is important for those of us with osteoporosis as it enhances G.I. absorption of calcium to help maintain bone mineral density (BMD), and it has hormonal functions in many other conditions, so maintaining a proper serum vitamin D level is quite important. See this abstract from Am J Clin Nutr. 2004 Dec;8076Suppl(:1678S-88S) by Holick JF for more details. The recommended blood concentration of vitamin D is above 80 nmol/L (approximately 30 ng/mL), and annual monitoring of serum 25-hydroxyvitamin D (25(OH)D) is recommended to prevent deficiency. Adequate levels can be reached by enough skin exposure to sunlight or with vitamin D supplements. There are several recent articles regarding this topic that I will highlight in the following discussions. J Clin Endocrinol Metab. 2009 Jan 27. [Epub ahead of print], Vitamin D Deficiency in Older Men. Orwoll E and others. PMID: 19174492. This study involved a large group of older men in the U.S. who did not spend much time in the sunlight. Even though 58% of the men were supplementing with vitamin D, their serum 25(OH)D was not optimum. The authors concluded, "Vitamin D deficiency is common in older men, and is especially prevalent in obese, sedentary men living at higher latitudes. Use of vitamin D supplements at levels reported here did not result in adequate vitamin D nutrition." This would lead one to presume that a high-potency vitamin D like vitamin D3, especially if taken in higher, less frequent doses that maintain adequate serum vitamin D levels, would be helpful for these older men. J Nutr. 2009 Jan 21. [Epub ahead of print]. Supplements of 20 {micro}g Cholecalciferol Optimized Serum 25-Hydroxyvitamin D Concentrations in 80% of Premenopausal Women in Winter. Nelson ML and others. PMID: 19158226. This study found that 20 mug/day of vitamin D3 (cholecalciferol) when given to women living in Maine in winter resulted in ". . . optimal 25(OH)D concentrations (>/=75 nmol/L) in 80% of participants, indicating that this dose is adequate to optimize vitamin D status in most young women in Maine." Whether this dose would be adequate for men is uncertain, and, since it involved a daily dose, it would be ideal to find one using much longer dosing intervals. Scand J Rheumatol. 2008 Nov 5:1-5. [Epub ahead of print]. The tolerability and biochemical effects of high-dose bolus vitamin D2 and D3 supplementation in patients with vitamin D insufficiency. Leventis P, Kiely PD. PMID: 18991184. This study used high-dose (300,000 IU) intramuscular (i.m.) vitamin D2 or D3 in people with insufficient 25(OH)D levels. The authors concluded, "The 300,000-IU bolus of vitamin D2 or D3 was practical, well tolerated, and safe. Vitamin D3 had greater potency than equimolar vitamin D2, with a higher, sustained serum 25(OH)D response and efficacious PTH suppression. To adequately treat vitamin D insufficiency we would recommend administering 300,000 IU oral vitamin D3 approximately three times per year." So this i.m. vitamin D3 three times yearly is an option that those unwilling or unable to take daily dosing should consider, especially those with documented low serum vitamin D levels. Int J Clin Pract. 2007 Nov;61(11):1894-9. Vitamin D therapy in clinical practice. One dose does not fit all. Ryan PJ. PMID: 17935548. This study warns against using one dose method for all individuals. This involved individuals taking Calcichew D3 Forte, two tablets daily. Although this was effective on some of the individuals, it did not get all of them to optimal vitamin D levels. The author concludes: "Vitamin D therapy with conventional treatment improves serum levels of 25 hydroxy vitamin D but still leaves some patients with significant insufficiency and therefore the same dose of vitamin D is not appropriate for all." So this study provides more reason to have your vitamin D levels tested at least annually. Based upon those results your dose of vitamin D3 could then be adjusted and further monitored. This would be titrating your body's response to the vitamin D supplement much as is done when treating hypothyroidism. Thus treating each person individually rather than with a one-dose-fits-all approach to gain more optimal results. Nutr Rev. 2008 Oct;66(10 Suppl 2):S178-81.Vitamin D: criteria for safety and efficacy. Heaney RP. PMID: 18844846. This article gives a few important figures to help us understand the potential toxicity of vitamin D supplements. Heaney points out that the ideal serum level of 25(OH)D is 80 nmol/L or higher with toxicity occurring at 500 nmol/L or higher. Thus showing the safety factor involved with normal supplement dosing or sunlight exposure. He notes we would have to take in excess of 20,000 IU/day to reach this toxic level. Editor's comments. This group of articles points out the importance of knowing that your serum vitamin D levels are in the normal range which is easily verified by serum 25(OH)D testing. Equally important would be to be sure that you get adequate supplements of vitamin D (most likely the D3 because of its higher potency) if you aren't staying at or near the correct 25(OH)D level. You might want to discuss using vitamin D3 with your care provider, especially after having your 25(OH)D level checked and find it inadequate.
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