Transcript vitamin d, 041707b - Biology East Los Angeles College

Background and Commentary on
The Call for Education and Research into
Vitamin D Deficiency
Christopher J. Jarosz, Ph.D.
County of Los Angeles
Public Health Department
Nutrition Program
April 17, 2007
Contents
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Biological aspects
Sources of vitamin D—dietary considerations
Sources of vitamin D—sunlight
Adequate intake of vitamin D
Occurrence of vitamin D deficiency
Further prevention of vitamin D deficiency
Call for education and research
Assessment of the call for research and education
Principal advocate, background information
National Osteoporosis Foundation guidelines
Estimated annual costs of an enhanced supplementation program
Summary and conclusions
Possible LAC Public Health position
References
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Biological Aspects1,2
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Vitamin D is a fat soluble vitamin that is found in some foods, and can be synthesized
by the body with exposure to UV(B) in sunlight.
Calciferol is the most active form of vitamin D.
Other forms are relatively inactive in the body, but can be converted by the liver and
kidneys to the active hormonal forms, 25 hydroxyvitamin D and 1,25 dihydroxyvitamin
D.
Vitamin D from dietary and cutaneous sources are interchangeable precursors of the
active hormone.3
The active hormone signals the small intestine to increase the absorption of calcium
and phosphorous.
Vitamin D helps to maintain bone strength by promoting calcium absorption in bone.
Vitamin D also promotes bone mineralization in concert with other vitamins, minerals,
and hormones.
Adequate levels of vitamin D prevent rickets in children and osteomalacia in adults.
Vitamin D may be associated with immune system health and regulation of cell
differentiation and growth.
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Sources of Vitamin D—Dietary Considerations1
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Vitamin D is contained in natural foods and fortified forms including:
– Cod liver oil
– Cooked salmon
– Canned tuna
– Canned sardines
– Fortified milk (and
– Fortified orange juice
– Fortified margarines
– Fortified ready-to-eat cereals
– Whole eggs
– Cooked beef liver
– Cheese
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International units (IU) and percent daily value (DV) of these foods are available from
the Office of Dietary Supplements, National Institutes of Health (NIH).
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Sources of Vitamin D—Sunlight1,2
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Adequate sunlight exposure provides many people with their vitamin D requirement
by enabling UV(B) rays to trigger vitamin D synthesis in the skin.
Factors affecting vitamin D synthesis in the skin include geographic latitude, cloud
cover, air pollution, shade, sunscreen usage (8 SPF or higher), and time of day.
For example, sunlight exposure in Boston (42o, 22’ north) is inadequate in the winter
months for vitamin D synthesis.
Typically, 10 to 15 minutes of sun exposure twice a week to the face, arms, hands, or
back allows for adequate vitamin D synthesis.
Diet should be supplemented with natural or fortified foods containing vitamin D when
sunlight exposure is insufficient.
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Adequate Intake of Vitamin D1
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The Institute of Medicine of the National Academy of Sciences determined Adequate Intake (AI)
guidelines for vitamin D.
Insufficient scientific information existed for establishing Recommended Daily Allowances
(RDA).
Adequate Intake (micrograms per day)
Age
Men
Women
Pregnancy
Lactation
14 – 18 years
5 (200 IU)
5 (200 IU)
5 (200 IU)
5 (200 IU)
19 – 50 years
5 (200 IU)
5 (200 IU)
5 (200 IU)
5 (200 IU)
51 – 70 years
10 (400 IU)
10 (400 IU)
71+ years
15 (600 IU)
15 (600 IU)
Birth – 13 years
Children
5 (200 IU)
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Occurrence of Vitamin D Deficiency1
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Vitamin D deficiency can be the result of:
– Intake below recommended levels
– Limited exposure to sunlight
– The liver and kidneys not converting vitamin D to its active hormonal form
– Inability of the small intestine to absorb vitamin D from foods
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Vitamin D deficiency is associated with milk allergies, lactose intolerance, and strict
vegetarianism.
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The re-emergence of rickets is associated with prolonged breast-feeding, increased
use of daycare, and extensive use of sunscreens.
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Breast-fed infants may have inadequate vitamin D unless they receive supplements.
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The American Academy of Pediatrics recommends vitamin D supplementation within
the first two months unless the child is weaned and given vitamin D fortified formula.
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Adults age 50 and over are at risk because of the reduction in the effectiveness of the
skin to synthesize vitamin D and a reduced capacity by the kidneys to convert vitamin
D to its active hormonal form.
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African Americans and some ethnic populations are at greater risk due to the high
melanin content of darker skin, which reduces vitamin D production in response to
UV(B) light.
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Further Prevention of Vitamin D Deficiency
“It can be difficult to obtain enough vitamin D from natural food sources. For many
people consuming vitamin D fortified foods and adequate sunlight exposure are
essential for maintaining a healthy vitamin D status. In some groups, dietary
supplements may be needed to meet the daily need for vitamin D.”1
Dietary Supplement Fact Sheet: Vitamin D. Office of Dietary Supplements, National
Institutes of Health. Website: http://ods.od.nih.gov/factsheets/vitamind.asp.
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Call for Education and Research4
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Azzie Young, Ph.D. (organic chemistry) and M.P.A. works for the Mattapan Community
Health Center in Boston and previously was in management at the Kansas Department
of Health and Environment.5
She states that vitamin D deficiency is a major epidemic in the United States affecting:
– 30 to 40 percent of children
– 40 to 50 percent of adults
Related NIH-published data are:1
– 42.4 percent of non-Hispanic African American women and 4.2 percent of nonHispanic white women (19 to 49 years) are vitamin D insufficient
– 30 to 40 percent of older adults with hip fractures are vitamin D insufficient
Dr. Young states about one billion people are affected world-wide, which would be onehalf to one-third of the prevalence she claims for the U.S.
Dr. Young states that diet and sunlight are typically inadequate for maintaining vitamin
D levels.
She recommends an increase in adult dosage levels to 1000 IU per day. She bases
this on the findings of “many experts” but primarily cites the papers of Michael F. Holick
of Boston University.
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Call for Education and Research (continued)
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Key conclusions of the Call for Education and Research paper are that public health
solutions exist through education campaigns and increased pharmacological doses of
vitamin D
Dr. Young suggests vitamin D deficiency is associated with a number of diseases (in
addition to rickets in children and osteomalacia in adults). The diseases include:4
– Breast, colon, prostate, and esophageal cancers, among other cancers
– Type I and type II diabetes
– Osteoporosis
– Multiple sclerosis
– Rheumatoid arthritis
– Hyperparathyroidism
– Hypertension and heart disease
The National Institutes of Health states there is:2
– Unclear scientific evidence in cancer, type I and II diabetes, multiple sclerosis,
and hypertension (rated “C”)
– Good scientific evidence in osteoporosis (rated “B”)
– Strong scientific evidence in hyperparathyroidism (rated “A”)
– No mention of other forms of heart disease and rheumatoid arthritis
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Assessment of the Call for Education and Research
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Dr. Young’s recommendations for an increase in vitamin D supplementation (to 1000
IU) are largely based on articles authored or co-authored by Michael Holick.
Dr. Holick and co-authors’ recommendation of 1000 IU of vitamin D appears to be
based on no more than three studies of colorectal cancer and blood serum levels of
1,25 dihydroxyvitamin D.6
Dr. Holick states the role of Vitamin D insufficiency in cancer, multiple sclerosis, type I
diabetes, and cardiovascular disease. He calls for increasing daily intake to 1000 IUD
based on wider, beneficial health effects.7
NIH states the scientific evidence is unclear for the association between cancer and
vitamin D.2
The role of Vitamin D supplementation in broader disease prevention also appears to
be overstated.
David A. Hanley and K. Shawn Davison recommend increasing vitamin D intake for
adults to 800 IU, primarily based on improving bone and muscle health in the elderly.8
The beneficial effects of increasing daily intake of Vitamin D beyond current Adequate
Intake guidelines have not yet been recognized by NIH and the National Academy of
Sciences.
Meeting current Adequate Intake guidelines for Vitamin D, however, should probably
remain a public health concern.
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Principal Advocate, Background Information
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Michael F. Holick, M.D., Ph.D. is probably the most well-known advocate of Vitamin D
pharmacological supplementation and increased human exposure to sunlight.
He is a Professor of Medicine, Physiology, and Biophysics at Boston University, has
published in various journals, and has authored popular books and layperson articles.
Dr. Holick is also an Academic Associate for Nichols Institute Diagnostics, which has
commercialized a number of bioassay methods, including for blood serum Vitamin D.
He advocates increased daily intakes of Vitamin D (1000 IU), and treats some of his
patients with much larger periodic dosages (up to 50x) for extended periods of time.9
He claims he has been vilified by the medical community for his views on the broad
health benefits of sun exposure (including protection against diabetes II and multiple
sclerosis). He claims that as a result he lost his faculty position in the Department of
Dermatology at Boston University.10
Dr. Holick authored or co-authored ten of the 26 papers referenced in Dr. Young’s,
“Call for Education and Research into Vitamin D Deficiency.” Only one of the other 60
report authors was cited more than one time (twice).3
Dr. Holick is not cited in the Vitamin D section of The Federal Government’s Medline
Plus,2 but he is cited in 9 of the 62 references in the NIH’s Vitamin D fact sheet,1 both
which are available on-line.
He gave an extensive interview on “The Healing Power of Sunlight & Vitamin D” in
2005.9 The 20-page article is part of Truth Publishing International‘s “The Healing
Power of” series.
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National Osteoporosis Foundation Guidelines11
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The National Osteoporosis Foundation announced updated guidelines for Vitamin D
and calcium intake on March 13, 2007.
The NOF website cites Dr. Holick and his co-authors as the only reference for their
recommendations.12
The guidelines, in comparison to the National Academy of Science guidelines on page
6 are:
– 800 – 1000 IU of vitamin D per day for adults 50 and older
– 1200 mg of calcium per day for adults 50 and older
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Estimated Annual Costs–Supplementation Program
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Dr. Young cites a reference that a pharmacological dose of 1000 IU of vitamin D would
cost less than five cents per day.3,5
The annual cost of vitamin D supplementation, assuming four cents per day, per
person, would be:
– County of Los Angeles (population 10 million): $73M (50 percent of residents) and
$146M (100 percent of residents)
– State of California (population 36 million): $262M (50 percent of residents) and
$525M (100 percent of residents)
– United States (population 302 million): $2,204M (50 percent of residents) and
$4,409M (100 percent of residents)
Although individual dosages are a few cents the cumulative costs for large populations
are substantial.
The possible need for periodic bioassays could add substantially to the overall costs.
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Summary and Conclusions
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Vitamin D serves important functions in maintaining healthy bodies throughout the
human lifespan.
Recommendations for dietary vitamin D intake were established by the Institute of
Medicine of the National Academy of Sciences.
Ample evidence indicates some people do not obtain the recommended daily intake
either through diet or exposure to sunlight.
A change in dietary practices or supplemental pharmacological doses of vitamin D
may be needed when Adequate Intake guidelines are not met.
The recommendation to increase daily vitamin D intake (to 1000 IU) appears to have
originated in a very small number of published papers.
The relationships between vitamin D and some diseases (e.g., cancer, multiple
sclerosis, type I and II diabetes, and hypertension) have not been established with
clear scientific evidence.
The cumulative nature of scientific evidence might someday lead to changes in our
understanding of a far wider role of vitamin D in disease prevention.
Pharmacological supplementation on a wide public scale has substantial dollar costs.
Perhaps the focus should be on healthy and balanced diets, and moderate exposure
to sunlight.
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Possible LAC Public Health Position
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We encourage all residents of Los Angeles County to eat healthy and balanced diets
including natural or enriched foods containing vitamin D.
We also encourage all residents of Los Angeles County to maintain adequate daily
calcium intake through healthy and balanced diets.
We encourage all residents of Los Angeles County to engage in physical activity and
spend time outdoors consistent with sun exposure guidelines.
We will respond to any changes to the vitamin D intake guidelines of the Institute of
Medicine of the National Academy of Sciences in updating nutritional guidelines and
policy.
What would be our position on supplemental pharmacological doses when National
Academy of Sciences intake guidelines are not met?
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References
1. _____. Dietary Supplement Fact Sheet: Vitamin D. Office of Dietary Supplements,
National Institutes of Health. Website: http://ods.od.nih.gov/factsheets/vitamind.asp.
2. _____. Vitamin D. Medline Plus, U.S. National Library of Medicine and the National
Institutes of Health. Website: http://www.nlm.nih.gov/medlineplus/druginfo/natural/
patient-vitamind.html
3. Young, A. Call for Education and Research into Vitamin D Deficiency. Publication
source unknown. March 15, 2007.
4. Wolpowitz, D and Gilchrest, BA. The Vitamin D Questions: How Much Do You Need
and How Should You get It? Journal of the American Academy of Dermatology.
February 2006; 54(2): 301-317.
5. _____. Young and Umemoto Elected to Section Council. American Public Health
Association, Fall 2006. Website: http://www.apha.org/membergroups/newsletters/
sectionnewsletters/comm/fall06.
6. Garland, CF, Garland, FC, Gorham, ED, Lipkin, M, Newmark, H, Mohr, SB, and Holick,
MF. The Role of Vitamin D in Cancer Prevention. American Journal of Public Health.
February 2006; 96(2): 252-261,
7. Holick, MF. High Prevalence of Vitamin D Inadequacy and Implications for Health.
Mayo Clinic Proceedings. March 2006; 81(3): 353-373.
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References (continued)
8. Hanley, DA and Davison, KS. Vitamin D Insufficiency in North America. Symposium:
Vitamin D Insufficiency: A Significant Risk Factor in Chronic Diseases and Potential
Disease-Specific Biomarkers of Vitamin D Sufficiency. Experimental Biology meeting
in Washington, DC, April 18, 2007. Reprinted by the American Society for Nutritional
Sciences, 2005: 332-37.
9. Adams, M. The Healing Power of Sunlight & Vitamin D: An Exclusive Interview with
Dr. Michael Holick. Truth Publishing International, 2005. Website:
http://www.truthpublishing.com.
10. O’Neill, B. They Have Vilified the Sun–and Me: Interview with Professor Michael
Holick, July 23, 2004. Website: http://www.spiked-online.com/articles.
11. Updated Recommendations for Calcium and Vitamin D3 Intake. National Osteoporosis
Foundation, March 13, 2007. Website: http://www.nof.org/prevention/calcium_and_
VitmaminD.htm.
12. Dawson-Hughes B, Heaney RP, Holick M, Lips P, Meunier P, Vieth R. Estimates of
optimal vitamin D status. Osteoporosis International. 2005; 16: 713-716 (cited by the
National Osteoporosis Foundation).
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