Download Nutritional Education in the USIn a 1991 survey, only 23%

Vitamin D: New Information about
an Essential Nutrient
• At the end of this workshop,
participants will be able to
– Understand the current concepts of the
role Vitamin D plays in human health,
the rational for Vitamin D supplements,
and not be afraid to claim their place in
the sun.
Resources and references
• Galland, Leo. Power Healing. 1997. Random House.
New York, NY
• Holick, Michael. The UV Advantage. 2003 Ibooks. New
York, NY
• Kuhn,Thomas. The Structure of Scientific Revolutions.
1970 University of Chicago Press. Chicago, IL
• Vasquez A et al The Clinical Importance of Vitamin D
(Cholecalciferol): A Paradigm Shift with Implications for
All Healthcare Providers. Alternative Therapies in Health
and Disease. Sept/Oct 2004. Vol. 10 No 5
• Willett, Walter Eat Drink and Be Healthy. 2001 Simon
and Shuster. New York, NY
Vitamin D is the most common
nutritional deficiency in the US
• What percent of the following groups are
Vitamin D deficient?
• Free-living and institutionalized elders__
• Boston medical students and residents at
the end of winter__
• African American women of childbearing
age at the end of winter__
The Answers
• What percent of the following groups
are Vitamin D deficient?
• Free-living and institutionalized
elders__>50%
• Boston medical students and
residents at the end of winter__32%
• African American women of
childbearing age at the end of
winter__41%
Forms of Vitamin D
Cholecalciferol (D3) is the naturally occurring form of
Vitamin D in the skin and in food. It is converted in the
liver to:
Calcidiol (25-hydroxy Vitamin D), which is considered a
“prehormone.” The calcidiol blood level is
measured to assess Vitamin D stores in the body.
Calcidiol is converted in the kidneys, breast, prostate,
ovary, pituitary, brain, etc to:
Calcitriol 1,25 hydroxy Vitamin D, which maintains
calcium in the blood and has an array of effects in
the body’s organs.
Ergocalciferol (D2) is a synthetic form of Vitamin D
used as a supplement.
Calcitriol, the most biologically active
form of vitamin D does the following:
Controls bone metabolism
Modulates neurotransmitter and neurological
function
Has immunoregulatory function and can
decrease inflammation (Autoimmune
disease such as multiple sclerosis)
Modulates transcription of several genes,
particularly those effecting differentiation
and proliferation (Cancer mortality)
Controls Bone Metabolism, cont.
– Increases calcium and phosphorous
absorption in the gut
– Induces osteoclast maturation for bone
remodeling
– Promotes calcium deposition in bone
(osteoblasts)
– Causes reduction in parathyroid
hormone (lower PTH levels correlate
with reduced risk of HTN, MI and stroke)
How much Vitamin D do we need?
RDA (Recommended Daily Allowance) vs. DRI’s (Optimal Intake)
• “The advent of the new dietary reference intakes (DRIs)
has redefined the role of recommended micronutrient
intakes and shifted the focus from prevention of nutrient
deficiency to reduction of disease risk. A key component
of this new approach is establishing reliable functional
indicators of nutrient status that may predict disease risk
before a severe nutrient deficiency ensues. The
identification and use of functional indicators is also
important in the determination of nutrient intakes
adequate to support key metabolic functions”
•
Reference: Rampersaud G et al Genomic DNA methylation decreases in
response to moderate folate depletion in elderly women American
Journal of Clinical Nutrition, Vol. 72, No. 4, 998-1003,
Vitamin D and Cancer
Research scientists in the 1980's had already discovered
that calcitriol had profound anti-cancer effects, both in
the test tube and in animals, through the following
mechanisms. Check which apply.
• __reduced the unregulated growth of cancer cells by promoting
normal cell death (apoptosis);
• __prevented new cells from becoming cancerous (promoted
differentiation).
• __helped prevent cancer cells from spreading (metastasis)
• __inhibited cancer cells from developing new blood supply
(angiogenesis). In short, calcitriol seemed like the perfect anticancer
drug
•
Answer: All are true
Sun exposure, Vitamin D and
cancer
Increased sun exposure is associated with what change in
risk of the following cancers: (increase /decrease/no
effect)
__Breast cancer
__Squamous cell cancer (1,500 deaths/year)
__Prostate Cancer (40,000 deaths/year)
__Lung Cancer
__Breast Cancer (50,000 deaths per year)
__Colon Cancer
__Malignant Melanoma (7,000 deaths per year)
__Ovarian Cancer
The Answers
Increased sun exposure is associated with what change in
risk of the following cancers: (increase /decrease/no
effect)
Decrease__Breast cancer
Increase__Squamous cell cancer (1,500 deaths/year)
Decrease__Prostate Cancer (40,000 deaths/year)
No Change__Lung Cancer
Decrease__Breast Cancer (50,000 deaths per year)
Decrease__Colon Cancer
Increase__Malignant Melanoma (7,000 deaths/year)
Decrease__Ovarian Cancer
Higher Vitamin D levels provide protection against
what other diseases? (Check all that are true)
•
•
•
•
•
•
•
•
_Diabetes mellitus type 1
_osteoporosis
_osteoarthritis
_hypertension
_cardiovascular disease
_metabolic syndrome and type 2 diabetes
_depression (especially SAD)
_certain autoimmune diseases (esp. MS)
Higher Vitamin D levels provide protection
against what other diseases?
•
•
•
•
x_Diabetes mellitus and metabolic syndrome
– Hypovitaminosis D is associated with increased insulin resistance in
diabetics and healthy adults
– Vitamin D supplementation was more effective than metformin in
improving insulin sensitivity in Type II diabetics
– Vitamin D supplementation in infants and children reduced the
incidence of Type I diabetes by 80%
x_osteoarthritis
– Progression of knee and hip arthritis is slowed by adequate levels of
Vitamin D (Framingham Study)
x_cardiovascular disease
– Cardiovascular deaths are more common in the winter, at higher
latitudes, and lower altitudes.
– Heart attack risk is higher for those with lower Vitamin D blood levels
– Vitamin D deficiency can contribute to congestive heart failure and
hypertension
x_depression (especially seasonal affective disorder (SAD)
Sunlight and Multiple Sclerosis
An estimated 330,000 Americans have Multiple sclerosis, a chronic
debilitating disease that affects the brain and spinal cord. Which of
the following statements are true:
• There is a genetic component to MS risk, with Northern Europeans
being at higher risk.
• You are 2 times more likely to get MS if you live in Europe or North
America than in the tropics
• The prevalence rate for MS is twice as high in the US above the 37th
parallel, then below.
• Exposure to the sun at any age decreases the likelihood of
developing MS
• Norwegians who live along the coast have a lower risk of MS than
those who live inland, and Eskimos who eat a traditional diet (bear
liver whale, seal blubber, oily fish) have almost no MS.
Sunlight and Multiple Sclerosis
• There is a genetic component to MS risk, with Northern Europeans
being at higher risk. TRUE
• You are 2 times more likely to get MS if you live in Europe or North
America than in the tropics. FALSE. Your are actually at a 5 times
higher risk.
• The prevalence rate for MS is twice as high in the US above the 37th
parallel, then below. TRUE. (The 37th parallel runs through Virginia)
• Exposure to the sun at any age decreases the likelihood of
developing MS. FALSE. Exposure to the sun before age 15 reduces
the risk of MS.
• Norwegians who live along the coast have a lower risk of MS than
those who live inland. TRUE. Coastal inhabitants eat more fish,
• Eskimos who eat a traditional diet (bear liver whale, seal blubber,
oily fish) have almost no MS. TRUE
Sources of Vitamin D
TRUE OR FALSE You can get adequate Vitamin D by:
__Exposure to UV rays for ¼ the time it would take your skin to redden
__Walking in the moonlight during a full moon
__Studying under bright fluorescent lights
__Spending Spring and Winter breaks snorkelling in the Bahamas
__Taking 1000 units (25 mg) of cholecalciferol (Vitamin D3) daily
__Taking the RDA (400 units per day) of ergocalciferol Vitamin D3)
daily
__Drinking 10 glasses of milk per day
__Taking 2 tsp of Cod Liver Oil daily
__Taking one tsp of Concentrated Fish Oil (Omega 3 Fatty Acids) daily
__Eating a 3 ½ oz serving of salmon per day
__Visiting a tanning salon regularly
The Answers
• TRUE OR FALSE You can get adequate Vitamin D by:
• T Exposure to UV rays for ¼ the time it would take your skin to
redden (4000-10000 IU)
• __Walking in the moonlight during a full moon
• __Studying under fluorescent lights
• T Spending Spring and winter breaks in the Bahamas
• T Taking 1000 units (25 mg) of cholecalciferol (Vitamin D3) daily
• __Taking the RDA (400 units per day) of ergocalciferol Vitamin D2)
daily
• T Drinking 10 glasses of milk per day (100 u Vitamin D/glass)
• T Taking 2 tsp of Cod Liver Oil daily (453 u Vitamin D/tsp)
• __Taking one tsp of Concentrated Fish Oil (Omega 3 Fatty Acids)
daily
• __Eating a 3 ½ oz serving of salmon/day (360 u Vitamin D)
• T Visiting a tanning salon regularly (4000-10000 IU)
What is a toxic level of Vitamin D?
•
•
•
•
A. 1,000 units per day
B. 2,000 units per day
C. 10,000 units per day
D. Greater than 10,000 units per day
What is a toxic intake of Vitamin D
• A. 1,000 units per day is at the lower end of a realistic
therapeutic intake for someone with limited sun exposure
• B. 2,000 units per day. This is the Food and Nutrition
Board’s previously defined upper limit which most, if not
all Vitamin D experts feel is far too low
• C. 10,000 units per day. Total-body sun exposure easily
provides the equivalent of 250 microg (10000 IU) vitamin
D per day/d, suggesting that this is a physiologic limit.
• D. More than 10,000 units/day, over a period of 2-3
months
•
Reference: Vieth R, Vitamin D supplementation, 25-hydroxyvitamin D
concentrations, and safety. Am J Clin Nutr. 1999 May;69(5):842-56.
What is a toxic intake of Vitamin D
• The assembled data from many vitamin D supplementation studies
reveal a curve for vitamin D dose versus serum 25-hydroxyvitamin D
[25(OH)D] response that is surprisingly flat up to 250 microg (10000
IU) vitamin D/d.
• Except in those with conditions causing hypersensitivity, there is no
evidence of adverse effects with serum 25(OH)D concentrations
<140 nmol/L, which require a total vitamin D supply of 250 microg
(10000 IU)/d to attain
• Published cases of vitamin D toxicity with hypercalcemia, for which
the 25(OH)D concentration and vitamin D dose are known, all
involve intake of > or = 1000 microg (40000 IU)/d.
• Because vitamin D is potentially toxic, intake of >25 microg (1000
IU)/d has been avoided even though the weight of evidence shows
that the currently accepted, “no observed adverse effect” limit of 50
microg (2000 IU)/d is too low by at least 5-fold.
Vitamin D from sun exposure
• Judiciously expose as much skin as possible to direct
midday sunlight for 1/4 the time it takes for the skin to
turn red, during those months when the proper ultraviolet
light occurs at their latitude (usually late spring, summer
and early fall).
• Do not get sunburned. Vitamin D production is already
maximized before your skin turns pink and further
exposure does not increase levels of vitamin D but may
increase your risk of skin cancer.
• Black persons may need five to ten times longer in the
sun than whites, depending on skin type.
• Topical application of an SPF of 8 will reduce the
cutaneous production of Vitamin D3 by 97.5%
Laboratory values of Vitamin D
Vitamin D 25Hydroxy is the important level for nutritional
adequacy (not Vitamin D1,25)
• Deficiency
– UVA norm 10-100 ng/ml
– MJH norm 20-100 ng/ml
– generally <20 ng/ml or <30ng/ml (Holick)
• Insufficiency <40 ng/ml
– Below level of 40-50 tissue levels are depleted and PTH
hormone levels begin to increase
• Optimal Vitamin D status 40-65 ng/ml (100-160 nmol/L)
– Some experts propose 80-100ng/ml as upper range
• Vitamin D excess
– May occur with levels >125 ng/ml
Vitamin D Supplementation
• Use D3 (cholecalciferol) rather than D2 (ergocalciferol)
– D3 is more efficient than D2 in raising and sustaining Vitamin D
levels.
• For correcting deficiency: Dosages should reflect
physiologic requirements and natural endogenous
production and should be in the range of 2,000-10,000
units per day
• Supplementation should be continued for 3-9 months
• Vitamin D levels do not plateau until 3-4 months.
• Most studies of Vitamin D supplementation have been flawed due to
insufficient therapeutic intervention
• Vitamin D levels should be monitored to assess effectiveness of
therapy, by measuring Vitamin D 25-hydroxy
• Vitamin D 1,25 levels do no reflect body stores of Vitamin D
• Supplements should be used that have been tested for potency
Vitamin D Supplementation
• For Maintenance (Persons with adequate
Vitamin D levels)
– Adults without sun exposure should receive 1000
units of Vitamin D daily, possibly more
– Pregnant women without sun exposure should
receive 1000 units of Vitamin D daily, possibly more
– Present recommendations of 200-600 units are
woefully inadequate
– Apart from fish and milk, there is very little Vitamin D
in food. Cheese, yogurt, ice cream, butter, etc. do not
contain significant amounts of Vitamin D,
– and 1/3 of milk samples contains none or less than
stated on the label.