Saude: Low Vit D Levels Linked to Cancer and Heart Disease

You are receiving this because you or someone at your email address subscribed to HealthBeat News

You are receiving this because you or someone at your email address subscribed to HealthBeat News. If you are receiving this in error, or wish to no longer receive this newsletter, please click here to unsubscribe.

Vitamin D - A Special HealthBeat News Report

29 March 2010

This Week In HealthBeat News:

Vitamin D - You have been reading about it in the news, and you have wondered what is real and what is hype.

Dr. Myatt and Nurse Mark have researched and prepared this special report for HealthBeat News Readers.

Vitamin D --- The Short Course

1.) Vit D is produced in our bodies in response to sun exposure. Vit D is also available from food and supplements.

2.) Vit D is FAR more important to health than was previously realized. I'm talking FAR more important.

3.) Vit D deficiency is widespread, including North America, even in sunny climates like Arizona. Many people who think they are getting enough Vitamin D from sunlight are mistaken.

4.) How to Optimize Vit D Levels for Good Health:

I.) Vit D test, supplement accordingly, re-test

II.) Supplement at 5,000IU for 3 months, then test your levels.

III.) Don't test, run the risk of being deficient, but take at least 2,000IU total per day. (This is still an extremely conservative dose, but much higher than the RDA of 400IU which hasn't been changed yet to reflect the newer findings about Vit D).

5.) Natural ways to obtain Vit D: Foods, supplements and sun exposure.

Vitamin D --- Nutrient of the Decade: Are You Getting Enough?

The Consequences of Low Vitamin D

Vitamin D is called "the sunshine Vitamin" because our bodies make it in response to sun exposure.

Vit D is necessary for normal bone formation in both children and adults. In children, deficiencies of Vit D lead to rickets. In adults, deficiencies are associated with osteoporosis and osteomalacia (soft bones), decreased muscle strength and increased risk of fall. ^{(1,12,14,22,43-48)} Until recently, the bone-protecting effect was about all that Vit D was known for, but the past decade of medical research has changed all that.

The newly appreciated Vitamin D deficiency risks include:

1.) heart disease: myocardial infarction, high blood pressure, heart failure, myopathy,
sudden cardiac death, stroke ^{(11,13-26, 30, 49-50)}

2.) blood sugar problems: glucose intolerance, diabetes mellitus, metabolic syndrome ^{(13-14,19,23-24,27-29)}

3.) cancer prevention and improved cancer survival rates ^{(7,8,11,14,15,24,31-37)}

4.) upper respiratory tract infections, influenza and tuberculosis ^(24,30,38)

5.) cognitive impairment and low mood ^(38-40)

6.) autoimmune disease (multiple sclerosis, RA, systemic lupus erythromatosis (SLE) ^{(15,24,26,29,30,32,41,42)}

7.) misc. diseases: psoriasis, polycystic ovarian syndrome, inflammatory bowel disease

8.) urinary incontinence ⁽⁵⁴⁾

9.) and all-cause mortality! ^{(5,6,7,24,30,51)}

How "significant" are these associations? Here are some of the conclusions of various studies and meta-analyses (lots of studies looked at together) concerning Vit D. Italics are mine for emphasis.

"Research strongly supports the view ... Vitamin D status would have significant protective effects against the development of cancer .... cancers of the breast, colon, prostate, ovary, lungs, and pancreas..." ⁽⁸⁾

"High levels of Vitamin D among middle-age and elderly populations are associated with a substantial decrease in cardiovascular disease, type 2 diabetes and metabolic syndrome." ⁽⁹⁾

"Low levels of [Vitamin D] are independently predictive for fatal strokes" ⁽¹⁰⁾

"It is estimated that there is a 30 to 50% reduction in risk for developing colorectal, breast, and prostate cancer by either increasing Vitamin D intake or increasing sun exposure..." ⁽¹¹⁾

"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" ⁽¹²⁾

" 28 studies including 99,745 participants ... highest levels of serum [Vit D] were associated with a 43% reduction in cardiometabolic disorders (cardiovascular disease, diabetes and metabolic syndrome) ..." ⁽⁹⁾

Are Your Vitamin D Levels Optimal? (Vitamin D Deficiency is Widespread)

One billion people worldwide are estimated to be Vit D deficient, and the problem affects us here in the United States as well. ⁽²⁾ One study found that more than half of North American women receiving drugs for prevention or treatment of osteoporosis were Vitamin D deficient. ⁽¹⁾ Another study found 48% of pre-adolescent girls to be Vit D deficient ⁽³⁾. Other studies have found that 40% to 100% of older men and women in both the United States and Europe are Vitamin D deficient.^[2] Because of the importance of Vit D and how widespread Vit D deficiency is, an estimated $100 to $200 billion is spent (wasted) each year on diseases which may really just be Vitamin D deficiencies. ^[4]

Age, overweight, dark skin color, use of sunscreen, and overprotection from the sun's rays are causes of decreased production of Vit D in response to sunlight. ^(52,52)

How Much Vitamin D Should You Take?

Ideally, you should take whatever amount of Vitamin D puts you in the "optimal" range. Since the amount will be highly variable depending on age, sex, race, weight, daily sun exposure and diet, there is no "one size fits all" answer. Instead, blood testing of Vitamin D levels and increasing intake until optimal levels are reached is the surest way to obtain optimal concentrations of Vitamin D in the body.

Deficiency	Insufficiency	Sufficiency^*	Optimal	Excess (Toxicity)
<20ng/ml	20-32ng/ml	32-100ng/ml	40-80ng/ml	> 150ng/ml

* - conventional medicine says that 30 ng/ml is "sufficient."
Chart references ^(59-62)

At the wellness Club we believe the most accurate and effective way to embark on a program of Vit D supplementation is to perform a Vit D test, supplement Vit D in accordance with the results, and then re-test in 3 months at which time your daily doses of Vit D can be fine-tuned for maintenance. March (right now!) is the best time to test initially because Vit. D stores tend to be lowest in this month.

The Vitamin D Council, a non-profit group dedicated to Vitamin D research and education recommends people take 5,000 IU per day for 2-3 months, then perform a Vitamin D test. They then suggest adjusting the dosage so that blood levels are between 50-80 ng/mL (or 125-200 nM/L) year-round. ⁽⁵⁵⁾

Alternately, some people opt to supplement without knowing their initial Vit D levels. A dose of 2000IU is quite conservative but certainly safe for almost anyone. In cases of significant Vit D deficiency conservative dosing such as this may take considerable time to rebuild healthy stores of this important Vitamin.

For those who wish to calculate their own Vit D requirements, 100 IU of Vitamin D could be expected to raise blood level of 25(OH)D by 1 ng/ml. ⁽¹¹⁾

Can too much Vitamin D can be toxic? Research shows that massive doses may eventually cause toxicity. One source found that in adults a sustained intake of 50,000 IU daily could produce toxicity within a few months ⁽⁵⁸⁾ and 40,000 IU per day in infants has been shown to produce toxicity within 1 to 4 months. ⁽⁵⁶⁾ That is ten times the recommended dose for each of those age groups! Vitamin D testing is good insurance that will allow you to safely fine-tune your dosage to your actual needs. Be careful though, since not all testing is the same and lab references and standards vary - be sure that you are comparing "apples to apples" and obtaining useable results when you are tested.

The 25-hydroxyVitamin D blood test (25(OH)D blood test) is a test that measures the amount of calcidiol circulating in the blood. This is the most accurate measure of the amount of Vitamin D in the body. The Wellness Club offers Vitamin D testing - performed by a lab that adheres to standardized references and values so that you know what you are getting when you receive your results. This can is performed at home with a "spot" (finger stick) blood test. Other tests that require a blood draw are also available.

How to Get to Your Optimal Vitamin D Levels

Start Vitamin D supplementation eight to twelve weeks before testing. Dr. John Cannell of the Vitamin D Council suggests a starting dose of 1,000 IU per 25 pounds of body weight. For example, a 150 pound person would take 6,000 IU Vitamin D per day. (150 divided by 25 = 6; 1,000IU x 6 = 6,000). Maintain this dose for 8-12 weeks, then test.

This dose may or may not put you in the optimal target range, but it certainly won't put you in any "toxic" range. Remember, most adults can safely take up to 10,000IU per day and still be far away from Vitamin D toxicity which typically appears at 40,000-50,000IU taken for several months.

Although this dose should theoretically put you in an optimal range, numerous personal variations alter Vitamin D requirements. Some people will need a higher dose than this calculation affords. However, taking the calculated dose should at least put you "in the ballpark" for optimal dosing.

When you test results come back, you can use the number to help you know whether or not you need to increase your Vit D dose and by how much. It is estimated that each 1,000 IU increase in supplemental Vitamin D will generally produce a 10 ng/ml increase in the Vitamin D blood level (8). If your test result shows that you are 10ng/ml below your target, increase daily Vit D intake by 1,000IU per day for a total of 7,000IU per day from the above example. Continue this dose and re-test in another 3 months to verify that you are now in your optimal range.

Congratulations! You have found your optimal daily Vitamin D intake needed to maintain optimal Vitamin D blood levels.

How to Obtain Vitamin D Naturally

Exposure to sun is the most natural way to boost Vit D levels. Medical scientists have found that the skin produces approximately 10,000 IU of Vitamin D in response to as little as 30 minutes of unprotected summer sun exposure.⁽⁵⁷⁾

Vitamin D can be obtained from food too. Since rickets in children is such a crippling but preventable condition, governments have long encouraged the "fortification" of dairy products and breads and cereals with token amounts of Vitamin D. In the United States and Canada, for example, fortified milk typically provides 100 IU per glass.

It is difficult to obtain optimal levels of Vitamin D from food alone.

Food	IUs per serving*	Percent DV**
Cod liver oil, 1 tablespoon	1,360	340
Salmon (sockeye), cooked, 3 ounces	794	199
Mushrooms that have been exposed to ultraviolet light to increase vitamin D, 3 ounces (not yet commonly available)	400	100
Mackerel, cooked, 3 ounces	388	97
Tuna fish, canned in water, drained, 3 ounces	154	39
Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup	115-124	29-31
Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies)	100	25
Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV)	80	20
Margarine, fortified, 1 tablespoon	60	15
Sardines, canned in oil, drained, 2 sardines	46	12
Liver, beef, cooked, 3.5 ounces	46	12
Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV)	40	10
Egg, 1 whole (vitamin D is found in yolk)	25	6
Cheese, Swiss, 1 ounce	6	2
IUs = International Units. *DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents of products within the context of a total diet. The DV for vitamin D is 400 IU for adults and children age 4 and older. Food labels, however, are not required to list vitamin D content unless a food has been fortified with this nutrient.

Table courtesy of the U.S. Government National Institutes of Health Office of Dietary Supplements

Although cod liver oil is high in Vitamin D, it is also high in Vitamin A which interferes with Vit D uptake, so cod liver oil is not the best supplemental form of Vit D. Keep daily intake of pre-formed Vitamin A to a maximum of 5,000IU per day so as not to interfere with Vitamin D absorption. Beta carotene does not appear to interfere with Vit. D uptake.

Vegetarians need to be sure they are getting plenty of sunshine, because other than tiny amounts that may be found in UV-irradiated mushrooms, there are no vegetable sources of Vitamin D.

The Bottom Line on Vitamin D

Achieving Optimal Vitamin D levels appears to be one of the most important things we can do for our overall health and life expectancy.

Please click on the image below enjoy an interesting and instructive video which discusses the relationship between Vitamin D and Cancer.

References

1.) Holick MF, Siris ES, Binkley N, et al. Prevalence of Vitamin D inadequacy among postmenopausal North American women receiving osteoporosis therapy. J Clin Endocrinol Metab. 2005;90: 3215-3224.
2.) Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357:266-281.
3.) Sullivan SS, Rosen CJ, Halteman WA, Chen TC, Holick MF. Adolescent girls in Maine at risk for Vitamin D insufficiency. J Am Diet Assoc. 2005;105:971-974.
4.) GrassrootsHealth. The Vitamin D deficiency epidemic. A call to D*action. http://www.grassrootshealth.org/daction/epidemic.php. Accessed May 8, 2009.
5.) GrassrootsHealth. Disease incidence prevention by serum 25(OH)D level. http://www.grassrootshealth.org/_download/disease_incidence_prev_chart_101608.pdf. Accessed May 8, 2009.
6.) Autier P, Gandini S. Vitamin D supplementation and total mortality. Arch Intern Med. 2007;167(16):1730-1737.
7.) Thomas L. Lenz. Vitamin D Supplementation and Cancer Prevention. Am J Lifestyle Med. 2009;3(5):365-368.
8.) Ingraham BA, Bragdon B, Nohe A. Molecular basis of the potential of Vitamin D to prevent cancer. Curr Med Res Opin. 2008 Jan;24(1):139-49.
9.) Parker J, Hashmi O, Dutton D, Mavrodaris A, Stranges S, Kandala NB, Clarke A, Franco OH. Levels of Vitamin D and cardiometabolic disorders: systematic review and meta-analysis. Maturitas. 2010 Mar;65(3):225-36. Epub 2009 Dec 23.
10.) Pilz S, Dobnig H, Fischer JE, Wellnitz B, Seelhorst U, Boehm BO, März W. Low Vitamin d levels predict stroke in patients referred to coronary angiography. Stroke. 2008 Sep;39(9):2611-3. Epub 2008 Jul 17.
11.) Holick MF. Vitamin D and sunlight: strategies for cancer prevention and other health benefits. Clin J Am Soc Nephrol. 2008 Sep;3(5):1548-54. Epub 2008 Jun 11.
12.) Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B. Fracture prevention with Vitamin D supplementation: a meta-analysis of randomized controlled trials. JAMA. 2005 May 11;293(18):2257-64.
13.) Anagnostis P, Athyros VG, Adamidou F, Florentin M, Karagiannis A. Vitamin D and Cardiovascular Disease: A Novel Agent for Reducing Cardiovascular Risk ? Curr Vasc Pharmacol. 2010 Feb 25. [Epub ahead of print]
14.) Holick MF. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr. 2004 Mar;79(3):362-71.
15.) Holick MF. Vitamin D and sunlight: strategies for cancer prevention and other health benefits. Clin J Am Soc Nephrol. 2008 Sep;3(5):1548-54. Epub 2008 Jun 11.
16.) Judd SE, Tangpricha V. Vitamin D deficiency and risk for cardiovascular disease. Am J Med Sci. 2009 Jul;338(1):40-4.
17.) Kendrick J, Targher G, Smits G, Chonchol M.25-HydroxyVitamin D deficiency is independently associated with cardiovascular disease in the Third National Health and Nutrition Examination Survey. Atherosclerosis. 2009 Jul;205(1):255-60. Epub 2008 Nov 11.
18.) Lee W, Kang PM. Vitamin D deficiency and cardiovascular disease: Is there a role for Vitamin D therapy in heart failure? Curr Opin Investig Drugs. 2010 Mar;11(3):309-14.
19.) Martins D, Wolf M, Pan D, Zadshir A, Tareen N, Thadhani R, Felsenfeld A, Levine B, Mehrotra R, Norris K. Prevalence of cardiovascular risk factors and the serum levels of 25-hydroxyVitamin D in the United States: data from the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2007 Jun 11;167(11):1159-65.
20.) McConnell JP, Foley KF, Vargas GM. HypoVitaminosis D: a new risk marker for cardiovascular disease. Clin Lab Sci. 2009 Fall;22(4):240-6.
21.) Mertens PR, Müller R. Vitamin D and cardiovascular risk. Int Urol Nephrol. 2009 Dec 29. [Epub ahead of print]
22.) Murlikiewicz K, Zawiasa A, Nowicki M. Vitamin D--a panacea in nephrology and beyond] Pol Merkur Lekarski. 2009 Nov;27(161):437-41.{article in Polish]
23.) Parker J, Hashmi O, Dutton D, Mavrodaris A, Stranges S, Kandala NB, Clarke A, Franco OH. Levels of Vitamin D and cardiometabolic disorders: systematic review and meta-analysis. Maturitas. 2010 Mar;65(3):225-36. Epub 2009 Dec 23.
24.) Pilz S, Dobnig H, Nijpels G, Heine RJ, Stehouwer CD, Snijder MB, van Dam RM, Dekker JM. Vitamin D and mortality in older men and women. Clin Endocrinol (Oxf). 2009 Nov;71(5):666-72. Epub 2009 Feb 18.
25.) Pilz S, März W, Wellnitz B, Seelhorst U, Fahrleitner-Pammer A, Dimai HP, Boehm BO, Dobnig H. Association of Vitamin D deficiency with heart failure and sudden cardiac death in a large cross-sectional study of patients referred for coronary angiography. J Clin Endocrinol Metab. 2008 Oct;93(10):3927-35. Epub 2008 Aug 5.
26.) Wu PW, Rhew EY, Dyer AR, Dunlop DD, Langman CB, Price H, Sutton-Tyrrell K, McPherson DD, Edmundowicz D, Kondos GT, Ramsey-Goldman R. 25-hydroxyVitamin D and cardiovascular risk factors in women with systemic lupus erythematosus. Arthritis Rheum. 2009 Oct 15;61(10):1387-95.
27.) Baz-Hecht M, Goldfine AB. The impact of Vitamin D deficiency on diabetes and cardiovascular risk. Curr Opin Endocrinol Diabetes Obes. 2010 Apr;17(2):113-9.
28.) Cheng S, Massaro JM, Fox CS, Larson MG, Keyes MJ, McCabe EL, Robins SJ, O'Donnell CJ, Hoffmann U, Jacques PF, Booth SL, Vasan RS, Wolf M, Wang TJ. Adiposity, cardiometabolic risk, and Vitamin D status: the Framingham Heart Study. Diabetes. 2010 Jan;59(1):242-8. Epub 2009 Oct 15.
29.) Holick MF. Sunlight and Vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr. 2004 Dec;80(6 Suppl):1678S-88S.
30.) Ginde AA, Scragg R, Schwartz RS, Camargo CA Jr. Prospective study of serum 25-hydroxyVitamin D level, cardiovascular disease mortality, and all-cause mortality in older U.S. adults. J Am Geriatr Soc. 2009 Sep;57(9):1595-603. Epub 2009 Jun 22.
31.) Grant WB. How strong is the evidence that solar ultraviolet B and Vitamin D reduce the risk of cancer?: An examination using Hill's criteria for causality. Dermatoendocrinol. 2009 Jan;1(1):17-24.
32.) Holick MF, Chen TC. Vitamin D deficiency: a worldwide problem with health consequences. Am J Clin Nutr. 2008 Apr;87(4):1080S-6S.
33.) Holick MF. Vitamin D: its role in cancer prevention and treatment. Prog Biophys Mol Biol. 2006 Sep;92(1):49-59. Epub 2006 Mar 10.
34.) Ingraham BA, Bragdon B, Nohe A. Molecular basis of the potential of Vitamin D to prevent cancer. Curr Med Res Opin. 2008 Jan;24(1):139-49.
35.) Pilz S, Dobnig H, Winklhofer-Roob B, Riedmüller G, Fischer JE, Seelhorst U, Wellnitz B, Boehm BO, März W. Low serum levels of 25-hydroxyVitamin D predict fatal cancer in patients referred to coronary angiography. Cancer Epidemiol Biomarkers Prev. 2008 May;17(5):1228-33. Epub 2008 May 7.
36.) Pilz S, Tomaschitz A, Obermayer-Pietsch B, Dobnig H, Pieber TR. Epidemiology of Vitamin D insufficiency and cancer mortality. Anticancer Res. 2009 Sep;29(9):3699-704.
37.) Ginde AA, Mansbach JM, Camargo CA Jr. Association between serum 25-hydroxyVitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009 Feb 23;169(4):384-90.
38.) Annweiler C, Schott AM, Allali G, Bridenbaugh SA, Kressig RW, Allain P, Herrmann FR, Beauchet O. Association of Vitamin D deficiency with cognitive impairment in older women: cross-sectional study. Neurology. 2010 Jan 5;74(1):27-32. Epub 2009 Sep 30.
39.) Cherniack EP, Troen BR, Florez HJ, Roos BA, Levis S. Some new food for thought: the role of Vitamin D in the mental health of older adults. Curr Psychiatry Rep. 2009 Feb;11(1):12-9.
40.) Wilkins CH, Sheline YI, Roe CM, Birge SJ, Morris JC. Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults. Am J Geriatr Psychiatry. 2006 Dec;14(12):1032-40.
41.) Cutolo M, Otsa K. Review: Vitamin D, immunity and lupus. Lupus. 2008;17(1):6-10.
42.) Kamen DL, Cooper GS, Bouali H, Shaftman SR, Hollis BW, Gilkeson GS. Vitamin D deficiency in systemic lupus erythematosus. Autoimmun Rev. 2006 Feb;5(2):114-7. Epub 2005 Jun 21.
43.) Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B. Fracture prevention with Vitamin D supplementation: a meta-analysis of randomized controlled trials. JAMA. 2005 May 11;293(18):2257-64.
44.) Bischoff HA, Stähelin HB, Tyndall A, Theiler R. Relationship between muscle strength and Vitamin D metabolites: are there therapeutic possibilities in the elderly? Z Rheumatol. 2000;59 Suppl 1:39-41.
45.) DIPART (Vitamin D Individual Patient Analysis of Randomized Trials) Group. Patient level pooled analysis of 68 500 patients from seven major Vitamin D fracture trials in US and Europe. BMJ. 2010 Jan 12;340:b5463. doi: 10.1136/bmj.b5463.
46.) Houston DK, Cesari M, Ferrucci L, Cherubini A, Maggio D, Bartali B, Johnson MA, Schwartz GG, Kritchevsky SB. Association between Vitamin D status and physical performance: the InCHIANTI study. J Gerontol A Biol Sci Med Sci. 2007 Apr;62(4):440-6.
47.) Kwon J, Suzuki T, Yoshida H, Kim H, Yoshida Y, Iwasa H. Concomitant lower serum albumin and Vitamin D levels are associated with decreased objective physical performance among Japanese community-dwelling elderly. Gerontology. 2007;53(5):322-8. Epub 2007 May 29.
48.) Pfeifer M, Begerow B, Minne HW. Vitamin D and muscle function. Osteoporos Int. 2002 Mar;13(3):187-94.
49.) Judd SE, Nanes MS, Ziegler TR, Wilson PW, Tangpricha V. Optimal Vitamin D status attenuates the age-associated increase in systolic blood pressure in white Americans: results from the third National Health and Nutrition Examination Survey. Am J Clin Nutr. 2008 Jan;87(1):136-41.
50.) Pilz S, Dobnig H, Fischer JE, Wellnitz B, Seelhorst U, Boehm BO, März W. Low Vitamin d levels predict stroke in patients referred to coronary angiography. Stroke. 2008 Sep;39(9):2611-3. Epub 2008 Jul 17.
51.) Melamed ML, Michos ED, Post W, Astor B.25-hydroxyVitamin D levels and the risk of mortality in the general population. Arch Intern Med. 2008 Aug 11;168(15):1629-37.
52.) Jacobs ET, Alberts DS, Foote JA, Green SB, Hollis BW, Yu Z, Martínez ME. Vitamin D insufficiency in southern Arizona. Am J Clin Nutr. 2008 Mar;87(3):608-13.
53.) Park S, Johnson MA. Living in low-latitude regions in the United States does not prevent poor Vitamin D status. Nutr Rev. 2005 Jun;63(6 Pt 1):203-9.
54.) Low Vitamin D Levels Tied to Incontinence. WebMD March 22, 2010 http://www.webmd.com/urinary-incontinence-oab/news/20100322/low-Vitamin-d-linked-incontinence.
55.) The Vitamin D Council. http://www.Vitamindcouncil.org/
56.) Wikipedia: Vitamin D. http://en.wikipedia.org/wiki/Vitamin_D
57.) Holick MF. Environmental factors thatinfluence the cutaneous production of Vitamin D. Am J Clin Nutr. 1995 Mar;61(3 Suppl):638S-645S.
58.) Vieth R. Vitamin D supplementation, 25-hydroxyVitamin D concentrations, and safety. Am J Clin Nutr. 1999 May;69(5):842-56.
59.) Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357:266-281.
60.) GrassrootsHealth. Disease incidence prevention by serum 25(OH)D level.http://www.grassrootshealth.org/_download/disease_incidence_prev_chart_101608.pdf. Accessed May 8, 2009.
61.) Dall T, Anderson J. Vitamin D: merging research into clinical lipid practice. Lipid Spin. 2008;6(3):4-8.
62.) Heaney RP. What is a Vitamin D deficiency?http://www.grassrootshealth.net/media/download/heaney_whats_Vitamin_d_deficiency120208.pdf. Accessed May 8, 2009.