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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Vitamin D and calcium requirements: conflicting opinions

In 2011, the Vitamin D and Calcium Dietary Guidelines Committee of the Institute of Medicine (IOM) of the National Academies published revised guidelines on vitamin D and calcium requirements9. The evidence used in preparing the guidelines was largely from randomized controlled trials (RCT’s) vetted by the Tufts Evidence-based Practice Center2. Observational studies were included only to the extent that they provided evidence of possible increased risk of adverse health outcomes at higher serum 25-hydroxyvitamin D [25(OH)D] concentrations. Benefits were identified only for bones. For people between the ages of 1 and 70 years, oral intakes of 600 IU/d vitamin D and serum 25(OH)D concentrations of 20 ng/ml (50 nmol/l) were recommended.

The Endocrine Society reviewed the data and found reasonable evidence for cancer, cardiovascular disease, and pregnancy, and subsequently recommended the following11:

“We suggest that all adults aged 50–70 and 70_ yr require at least 600 and 800 IU/d, respectively, of vitamin D to maximize bone health and muscle function. Whether 600 and 800 IU/d of vitamin D are enough to provide all of the potential nonskeletal health benefits associated with vitamin D is not known at this time. However, to raise the blood level of 25(OH)D above 30 ng/ml may require at least 1500–2000 IU/d of supplemental vitamin D.”

This month, the IOM committee members responded to the Endocrine Society’s rebuttal. They dug in their heels and did not accept any evidence for non-skeletal benefits8. The Endocrine Society committee responded by providing evidence that even for skeletal effects, the evidence supports values higher than 20 ng/ml and 600 IU/d vitamin D, and also provided more evidence for non-skeletal benefits4.

The position of the IOM committee is very difficult to understand. For one thing, the evidence of non-skeletal benefits has increased since the reviews by Chung et al.2 and Ross et al.9 were published.

For another, the concern about adverse effects of higher 25(OH)D concentrations is based solely on prospective observational studies in which a single serum 25(OH)D concentration at time of enrollment is used, with a follow-up period lasting anywhere from three to 28 years. As follow-up time increases, the usefulness of that single value decreases3,10. Case-control studies, in which serum 25(OH)D concentration is measured at the time of diagnosis, do not show any U-shaped response for cancer1.

Based on the rapidly rising journal literature on the benefits of vitamin D and the absence of adverse effects, it appears that the IOM report is best ignored and that those interested in determining optimal serum 25(OH)D concentrations and oral intake amounts consider 40 ng/ml (100 nmol/l) and 1000-5000 IU/d vitamin D3 as the values that correspond more closely with what nature suggests7. However, there is considerable individual variability in serum 25(OH)D concentration vs. oral intake6, so testing of serum 25(OH)D concentration may be advisable.

As for pregnancy and lactation, Bruce Hollis and colleagues showed that it takes about 4000 IU/d vitamin D3 to increase serum 1,25-dihydroxyvitamin D concentrations to optimal concentrations and to provide sufficient native vitamin D (cholecalciferol) in breast milk for the nursing infant5.

For those wishing more information on the health benefits of vitamin D, there are a number of documents at http://www.vitamindcouncil.org/health-conditions/, and those wishing to see the original journal articles may find links to them at www.pubmed.gov.


  1. Abbas S, Chang-Claude J, Linseisen J. Plasma 25-hydroxyvitamin D and premenopausal breast cancer risk in a German case-control study. Int J Cancer. 2009 Jan 1;124(1):250-5.
  2. Chung M, Balk EM, Brendel M, Ip S, Lau J, Lee J, et al. (2009). Vitamin D and calcium: a systematic review of health outcomes. Evid Rep Technol Assess (Full Rep)(183), 1-420. (Prepared by Tufts Evidence-based Practice Center under Contract No. 290-2007-10055-I). AHRQ Publication No. 09-E015, Rockville, MD: Agency for Healthcare Research and Quality. August 2009. (http://www.ahrq.gov/downloads/pub/evidence/pdf/vitadcal/vitadcal.pdf)
  3. Garland CF, French CB, Baggerly LL, Heaney RP. Vitamin D supplement doses and serum 25-hydroxyvitamin D in the range associated with cancer prevention. Anticancer Res 2011:31: 617-22.
  4. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM. Guidelines for preventing and treating vitamin D deficiency and insufficiency revisited. J Clin Endocrinol Metab. 2012;97(4):1153-8.
  5. Hollis BW, Johnson D, Hulsey TC, Ebeling M, Wagner CL. Vitamin D supplementation during pregnancy: double-blind, randomized clinical trial of safety and effectiveness. J Bone Miner Res. 2011 Oct;26(10):2341-57.
  6. Jorde R, Sneve M, Hutchinson M, Emaus N, Figenschau Y, Grimnes G. Tracking of serum 25-hydroxyvitamin D levels during 14 years in a population-based study and during 12 months in an intervention study. Am J Epidemiol. 2010 Apr 15;171(8):903-8.
  7. Luxwolda MF, Kuipers RS, Kema IP, Janneke Dijck-Brouwer DA, Muskiet FA. Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. Br J Nutr. 2012 Jan 23:1-5. [Epub ahead of print]
  8. Rosen CJ, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu RA, Gallagher JC, Gallo RL, Jones G, Kovacs CS, Manson JE, Mayne ST, Ross AC, Shapses SA, Taylor CL. IOM Committee members respond to Endocrine Society Vitamin D Guideline. J Clin Endocrinol Metab. 2012;97(4):1146-52.
  9. Ross AC, Manson JE, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu RA, Gallagher JC, Gallo RL, Jones G, Kovacs CS, Mayne ST, Rosen CJ, Shapses SA. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011 Jan;96(1):53-8.
  10. Grant WB. Effect of interval between serum draw and follow-up period on relative risk of cancer incidence with respect to 25-hydroxyvitamin D level; implications for meta-analyses and setting vitamin D guidelines. Dermato-Endocrinology. 2011;3(3):199-204.
  11. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab, 2011 Jul;96(7):1911-30.

  About: Dr William Grant

Dr. William Grant is an epidemiologist and founder of the nonprofit organization Sunlight, Nutrition and Health Research Center (SUNARC). He has written over 140 peer-reviewed articles and editorials on vitamin D and health. Dr. Grant is the Science Director of the Vitamin D Council and also serves on their Board. He holds a Ph.D. in Physics from UC Berkeley.
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4 Responses to Vitamin D and calcium requirements: conflicting opinions

  1. The IOM may be digging in it’s heels because of pressure from the industrial medical complex but I do not have direct evidence of such. What happens to the medical industry’s income if most of the population normalizes it’s D level by taking, say 5000 iu/day, D3?

  2. Don says:

    Same thing that happens to Big Pharma if everyone normalizes Vitamin D, same thing that happens to the Cancer Industry if laetrile were legalized, etc.

  3. Calcium and other co-factors are required as well
    While it was in the title, Dr.Grant neglected to mention the importance of Calcium and other co-factors.
    Calcium: 500 mg (max); Magnesium: 500 mg daily (minimum); Vitamin K2: 5-10 mg ; Boron: 5-10 mg, Silicon: 2 mg and some amount of Strontium
    are needed to build bones (increase BMD). A few other co-factors also increase the bio-availability of vitamin D.
    The Institute of Medicine is just one of many organizations which have failed to notice that when increasing vitamin D that it is essential that Calcium be reduced (to 500 mg) and Magnesium be increase (to 500 mg).
    Many studies have shown that just increasing vitamin D does NOT necessarily increase bone density if the co-factors are not also considered.
    Details at: http://www.vitamindwiki.com/tiki-view_blog_post.php?postId=80

  4. Personal opinion, alone, and is of no part of my employer:
    If vitamin D levels were returned to the pre-1986 levels in the typical US population, as a pharmacist I have become entirely certain that I would be dispensing 50% LESS prescriptions each day, primarily the type I call the “lifetime” palliative meds that will never cure but just offer the chance at great cost and risk of severe adverse effects of the possible suppression of a symptom(s) – the very symptoms avoidable to some profound level were only all concerned in heathcare delivery today were to militate cautiously to a standard blood level in each patient of 50 ng/ml. “healthy” or not, just as a general, FUNDAMENTAL measure of prudence. Along with temp, bp, heart rate, weight, height, etc, the marker of a 25 (OH)D level should be determined/established parameter the practitioner should routinely consider as part of the basic health assessment upon initial presentation. And, NEVER, EVER, should a patient accept from a doctor the phrase “your vitamin d blood level is ok” – FIGHT for the actual number – chances are high that “his/her” opinion of “ok” is a crappific 10 ng/ml based on the doc’s poor training. Find out that supposed ok number, and get it to 50 ng/ml. as soon as possible. Then monitor actively your symptoms’ responses to “mere” vitamin D. It may take as little time as two weeks, or as long as months, but it is worth considering for a variety of logical and soundly safe scientific reasons. The LEAST of which is the lessening of prescription use, cost, and risk.