Vitamin D:
From Sunshine to Supplements
2010 - 2011
Family and Consumer Sciences
Lesson
Vitamin D:
For Bones, and Beyond!
“We estimate that
Vitamin D deficiency
is the most common
medical condition in
the world.”
Vitamin D Crystals
Michael Holick, MD, PhD
noted Vit. D researcher,
Boston U. Med Center
Participants will…
 Recognize key functions of vitamin D
 Be able to list three or more diseases associated
with low vitamin D levels
 Identify ways to improve own vitamin D level
“Sunshine Vitamin”
is in the spotlight!
 3 out of 4 in U.S. have low levels of vitamin D
 Levels down in past 20 years
 Research reveals new understanding of our need for
vitamin D
Vitamin D then…
 Problem recognized for centuries,
in form of rickets
 In 1919, vitamin D discovered – key
to good bone formation
 Cod liver oil found to solve
deficiency
 Vitamin D added to milk in US
beginning in 1930s
Vitamin D research now
 Low vitamin D levels now linked to:
– decreased glucose tolerance
– cardiovascular disease
– multiple sclerosis
– rheumatoid arthritis
– types 1 and 2 diabetes
– at least 15 types of cancers
– chronic gum disease
– depression and falls in older adults
We now know…
 Vitamin D3, cholecalciferol, is produced in
human skin in presence of sunlight
 Is key in mineral metabolism, bone formation
with calcium
 Not actually a vitamin – functions in the human
body as a hormone, targeting over 36 organs!
 Vitamin D is stored in the body
 Humans make and require vitamin D at different
levels, so recommendations are difficult
“D”tails:
The Making of Vitamin D in Humans
 Wintertime, clouds, sunscreen, smog, body fat
and darkly pigmented skin reduce body’s
ability – also heavy veils worn in some
cultures
 Persons who stay inside and have poor diets
may have deficiency
 Exposure to sunlight cannot cause vitamin D
toxicity – only supplements can
How Vitamin D is measured
 Blood levels of 25-hydroxyvitamin D [written
as 25(OH)D] in healthy persons is best
indicator of vitamin D status
– Storage form
– Determined by simple blood test
– Most experts agree that levels below 50
nmol/L (or 20ng/mL) indicate deficiency
Symptoms of Vitamin D deficiency
Symptoms are subtle!
 Difficult to connect
varied symptoms –
can affect bones,
depression, blood
pressure, immunity
 Blood test is needed
to be certain
How much Vitamin D is enough?
 New recommended levels believed adequate
amount needed to prevent illness, other
deficiency “symptoms”
 Some researchers recommending levels at
5000 IU per day, but official recommendations
do not support this level
 Cannot make leap from basic science to public
health recommendations
 Individual needs do vary, depending on age
and health, diet, skin color, even history of
certain diseases & medicines. Obesity may
also affect deficiency
New Current DRIs for Vitamin D
(in International Units)
Life Stage
Vitamin D
 Infants 0-6 mos
400
 7-12 months
400
 Children 1-3 yrs
600
 4-8 years
600
Males 9-13 years
600
 14-18 years
600
 19-30 years
600
 31-50 years
600
 51-70 years
600
 > 70 years
800
New DRIs for Vitamin D (in IU),
cont’d.
Females 9-13 years
14-18 years
19-30 years
31-50 years
51-70 years
>70
Pregnancy < 18 yrs
19-30 years
31-50 years
Lactation 18 years
19-30 years
31-50 years
600
600
600
600
600
800
600
600
600
600
600
600
Vitamin D – Essential at all ages
Vitamin D in pregnancy
 Emerging research ties pre-
eclampsia with low vitamin D
levels in pregnancy
 Adequate vitamin D in pregnancy
may help prevent future cancer,
diabetes and heart disease in child
 Strong resurgence of rickets since
1990s, in dark-skinned infants who
were exclusively breast fed
New pregnancy and lactation
recommendation of 600 IU per
day from foods and supplements
Breast milk and Vitamin D
 Recurrence of infant rickets since
1990s, especially in dark-skinned,
breastfed infants, points to need for
increased vitamin D in the very
young
 A supplement of 400 IU per day of
vitamin D is recommended for all
breastfed infants
 The vitamin D content of human
milk is directly related to the
mother’s vitamin D status (Wagner,
et al., 2008)
Is breast milk lacking by design?
The research says…
 A daily vitamin D3
supplement is necessary for
mother during
breastfeeding, because the
circulating D3 moves into the
milk and affects its anti-ricket
activity
 Breastfed infants are at risk
for vitamin D deficiency
The American Academy of
Pediatrics has stepped in…
 Increased previous recommended amount
for all children, adolescents
from birth - age 18
 Advises 400 IU
supplemental vitamin D each
day, beginning within 2 months of birth
 New DRIs set at 600 IU for children age 1 or older
 A result of evidence of vitamin D’s role in bone
health
During childhood…
Vitamin D builds bone in tandem with
calcium
Immune system matures with adequacy
Obesity traps vitamin D in body fat – it is
made by body but not available for its use
Supplement encouraged in most cases
During adult years…
 Possible connections
to diseases and
medical problems
– diabetes
– high blood pressure
– colon, prostate, breast
cancers
– autoimmune
conditions
• multiple sclerosis
• rheumatoid arthritis
Sunlight as vitamin D source
 Sunlight is a valuable though
uneven source, due to variations in
many factors:
– Age, wintertime, clouds,
sunscreen, smog, body fat and
darkly pigmented skin reduce
body’s ability – also heavy veils
worn in some cultures
 Even those exposed to sun may
have limited skin area exposed,
and still be vitamin D deficient
In Kansas…
 Only able to produce vitamin D in the sunlight from
March through October
– We need to apply sunscreen AFTER 15 minutes of
direct sun exposure, in order to maximize vitamin D
production
– Angle of the sun is too
indirect the rest of the time
 Supplements are recommended
when sunlight is inadequate
Other than the sun…
 Vitamin D is found
naturally in very few foods
– Oily fish
•
•
•
•
•
Cod
Salmon
Tuna
Swordfish
Sardines
– Egg yolk
– Butter
– Liver
 Added to milk, in low
concentrations
Vitamin D sources, continued…
 D3 is preferred, active form
now added to increasing
number of foods such as
juice, yogurt, cereals
 Supplements recommended
for most people – often in
combination with calcium
 Tanning beds NOT
considered a safe,
dependable method to
increase vitamin D levels
Too much of a good thing?
 Toxicity is possible, as vitamin D is stored in
the body and will build up over time
 Excess vitamin D a result of supplements,
not from food or sun
 Safe upper level (UL) intake also set by IOM
– Age dependent
– Set at 4,000 IU/day for those age 9 and above
– NOT amounts people need or should consume
Big changes have been announced
 The Institute of Medicine
reviewed recent research,
and released new findings
on November 30, 2010
 “Current evidence does
not support benefits
beyond bone health, but
targeted research should
continue.”
Steps you can take…
 Talk with your health care provider
to see if you need your vitamin D
level tested
 Let the sun shine – safely! Find out
how much sunlight is right for you
 Focus on food sources of vitamin D
 Ask if your meds affect your
vitamin D level
 Find out if a supplement is right for
you
Need more info on vitamin D?
For more information, go to:
http://ods.od.nih.gov/factsheets/VitaminD-Consumer.asp
Thank you!
Sandy Procter, PhD, RD
Department of Human Nutrition
204 Justin Hall
Manhattan, KS 66506