Vitamin D depletion and is it a super vitamin?
Vitamin D depletion. Osteoporosis Int 2007 Sep 18; [Epub ahead of print], Prevalence of vitamin D depletion among subjects seeking advice on osteoporosis: a five-year cross-sectional study with public health implications. Guardia G and others. PMID: 17876644. This study included all the patients seeking osteoporosis advice in the Bone and Mineral Clinic at Henry Ford Hospital, Detroit, MI, U.S.A., between January 1, 1997 and December 31, 2001. Serum calcium, creatinine, PTH and 25-hydroxyvitamin D (25OHVD) were measured at the first visit. The study's goal was to measure vitamin D depletion defined by various cut-off points. Included were 2,924 people with a mean age of 68.3 + 10 years, with 90% women, and 87% white. The prevalence of vitamin D depletion according to three different cut-off points was:
25OHVD <15 ng/ml - 15%
25OHVD <20 ng/ml - 32%
25OHVD <30 ng/ml - 72%
At every cut-off point there was a significantly higher percentage of blacks that were 25OHVD-depleted than were whites. The various cut-off points were included because each one has been suggested as a vitamin D deficiency point by some authors. Obviously, if the various cut-off points are valid definitions of vitamin D deficiency, then many older individuals need vitamin D supplementation via sunshine or supplements. The authors state: "We conclude that vitamin D depletion is high among ambulatory patients seeking advice about osteoporosis. This implies that the current efforts and/or recommendations are either inadequate, ineffective or both, and are in need of urgent reexamination."
Editor's comments: The high cut-off point appears to be the safest from a fracture prevention perspective. See Osteoporos Int. 2005 Jul;16(7):713-6, Estimates of optimal vitamin D status. Dawson-Hughes B and others. PMID: 15776217. These authors are recommending between 50 and 80 nmol/l as the best point. This converts to 20 to 32 ng/ml. See this Update for information on converting the various methods that report serum vitamin D status. To reach these serum levels, Dawson-Hughes suggests that older individuals will need to take 800-1,000 IU vitamin D daily. Assuming the ideal is at least 30 ng/ml, the Guardia and others study shows that 72% of the population seeking information about osteoporosis needs some additional sunshine or a vitamin D supplement.
Is vitamin D a super vitamin? I have seen online articles recently regarding all the things that vitamin D works to prevent or treat. Here's an article by Bill Sardi that mentions vitamin D's involvement in bone-related diseases (as those with osteoporosis realize), sixteen cancer types, psoriasis, diabetes, high blood pressure, heart disease, multiple sclerosis, and susceptibility to tuberculosis. Sardi references multiple articles in his discussion. I am going to give you the PubMed PMID for each reference so you can read for yourself the science backing statements in "Just One Pill Away." My PMID listings will be in the same order that he mentions each article. After you've read this, you can decide for yourself if vitamin D is a super vitamin, and how concerned we should be about getting too much or not getting enough vitamin D.
Am J Clin Nutr. 2001 Feb;73(2):288-94. Efficacy and safety of vitamin D3 intake exceeding the lowest observed adverse effect level. Vieth R, Chan PC, MacFarlane GD. PMID: 11157326.
Am J Clin Nutr. 1999 May;69(5):842-56. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. Vieth R. PMID: 10232622.
Am J Clin Nutr. 2007 Jan;85(1):6-18. Risk assessment for vitamin D. Hathcock JN and others. PMID: 17209171.
J Cosmet Dermatol. 2003 Apr;2(2):86-98. Sunshine is good medicine. The health benefits of ultraviolet-B induced vitamin D production. Grant WB, Strange RC, Garland CF. PMID: 17156062.
J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):635-41. Epub 2007 Jan 10. The case for improving vitamin D status. Heaney RP. PMID: 17222549.
Osteoporos Int. 2007 Mar;18(3):251-9. Epub 2006 Dec 7. Vascular calcification and osteoporosis--from clinical observation towards molecular understanding. Hofbauer LC and others. PMID: 17151836.
Curr Opin Lipidol. 2007 Feb;18(1):41-6. Vitamin D and vascular calcification. Zittermann A, Schleithoff SS, Koerfer R. PMID: 17218831.
Am J Public Health. 2006 Feb;96(2):252-61. Epub 2005 Dec 27. The role of vitamin D in cancer prevention. Garland CF and others. PMID: 16380576.
Photochem Photobiol. 2005 Nov-Dec;81(6):1276-86. Comparisons of estimated economic burdens due to insufficient solar ultraviolet irradiance and vitamin D and excess solar UV irradiance for the United States. Grant WB, Garland CF, Holick MF. PMID: 16159309.
Am J Prev Med. 2007 Mar;32(3):210-6. Optimal vitamin D status for colorectal cancer prevention: a quantitative meta analysis. Gorham ED and others. PMID: 17296473.
Epidemiol Infect. 2006 Dec;134(6):1129-40. Epub 2006 Sep 7. Epidemic influenza and vitamin D. Cannell JJ and others. PMID: 16959053.
Am J Geriatr Psychiatry. 2006 Dec;14(12):1032-40. Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults. Wilkins CH and others. PMID: 17138809.
Clin Pediatr (Phila). 2007 Jan;46(1):42-4.. Vitamin D deficiency in a healthy group of mothers and newborn infants. Lee JM and others. PMID: 17164508.
Steroid Biochem Mol Biol. 2007 Mar;103(3-5):620-5. Epub 2007 Feb 6. Vitamin D status and nutrition in Europe and Asia. Lips P. PMID: 17287117.
Recent Results Cancer Res. 2007;174:225-34. An estimate of cancer mortality rate reductions in Europe and the US with 1,000 IU of oral vitamin D per day. Grant WB, Garland CF, Gorham ED. PMID: 17302200.
Photochem Photobiol. 2005 Nov-Dec;81(6):1276-86. Comparisons of estimated economic burdens due to insufficient solar ultraviolet irradiance and vitamin D and excess solar UV irradiance for the United States. Grant WB, Garland CF, Holick MF. PMID: 16159309.
Editor's comments: Logically vitamin D could be a "super" vitamin. Viewing the issue from an evolutionary standpoint, early humans would have gotten massive vitamin D doses from sunshine since their clothing was minimal or nonexistent and they were outside hunting, gathering, or otherwise working much of their lives. In fairly recent times we have made "revolutionary" changes in our lifestyles, not the gradual changes that evolution needs to make normal adjustments. So people used to living with high serum vitamin D levels began to exist with much lower levels. The immune and other systems would not have had time to acclimate to the lower changes in normal serum vitamin D levels that our current lifestyles give us. Modern societies have many people inside due to work or play, several cultures wear head-to-toe clothing, and sunscreens have become popular in the last few decades. All this leads to lower serum vitamin D levels in many people. The information above indicates that we (in general) need to get more vitamin D either via sunshine or supplements. If we do, the effect on the variety of diseases mentioned can be quite dramatic while being both life- and money-saving. First have your serum vitamin D levels tested to be sure you are in the 30 ng/ml range. Then adjust either the sunshine you get and/or your oral vitamin D intake to keep your serum vitamin D in the normal range. Safety suggests you err on the high side, with previous warnings about toxicity from excess vitamin D being far too conservative. For older individuals 800 to 1,000 IU of vitamin D daily would have no toxicity risk while offering benefits for osteoporosis and the other conditions described above.