Know your (Vitamin) D- factor
Vitamin D:
The “Super-Vitamin”
Vitamin D was
once thought to be just another vitamin that was just as important to your
health as all the other vitamins. We know it plays a huge role in
the regulation and absorption of Calcium, (that’s why you will see it in
your Calcium supplements) but it’s just over the past several years that
people are “doing extra D” for important added benefits...and rightly so!
The major
biologic function of vitamin D is to maintain normal blood levels of calcium
and phosphorus. Vitamin D aids in the absorption of calcium, helping to form
and maintain strong bones. Recently, research also suggests vitamin D may
provide protection from hypertension (high blood pressure), cancer, and several
autoimmune diseases including Multiple Sclerosis, Diabetes, and Rheumatoid
Arthritis.
Vitamin D is a
somewhat “special” vitamin as well because the body actually manufactures
Vitamin D from sunlight. No other
vitamin is produced in our systems.
The fact that our bodies produce it and the fact that it has such an
impact on many of our bodies systems, actually puts it in the category of a
hormone. This all important
“super-vitamin-y hormone” has made headlines recently because of the link that
was discovered with breast cancer.
Vitamin D
and Breast Cancer
It was found
that a significant number of breast cancer patients, for whatever reason, had
very low levels of Vitamin D. It was suggested that increasing women’s
Vitamin D level to “adequate” (35-74 ng/ml in the blood measured as
calcifediol or Vitamin D 25-hydroxy) could save 65,000 women from
developing breast cancer every year. A study of over 1400 women in the
general population showed that over 50% of them had inadequate Vitamin D
levels. (myself included)
When I was
diagnosed with stage III breast cancer my Vitamin D level was 23 ng/dl!
(desirable is considered to be 35 - 74 ng/dl) A few weeks of high dose vitamin D under a doctor’s
supervision, with a daily supplement intake of 4000 mg/day is keeping me in the
50’s.
Since the
breast cancer study, it has been discovered that other cancer patients as well
had low Vitamin D levels (but not prostate cancer). We are learning more and more about vitamin D and the role
it plays on your immune system.
Poor immunity is related to your risk of cancer, but also is linked to
heart disease, arthritis, diabetes, and Multiple Sclerosis among others. the reason is the role Vitamin D plays
in “apoptosis” or regulating the destruction of unwanted cells. A lapse in the regulation causes
overgrowth.....cancer.
It would make
sense, then, to assume that it is vital you know what your Vitamin D levels are
and supplement to keep them stable.
This can be done with a simple blood test called “serum
25-hydroxyvitamin D”. This has
become a very routine blood test and it is the only way to know if you are
getting enough D. With repeated
tests you can tell what “your
personal” level of supplementation is in order to keep you within range. The fact that Vitamin manufacturers are
now making Vitamin D in 2000 mg sized pills tells you that people are wising
up.
D2 vs D3
Vitamin D comes
in two forms when buying supplements. Vitamin D2 (ergocalciferol) comes from
plant sources, and Vitamin D3 (cholecalciferol) comes from animal sources. Your body produces vitamin D3 from
sunlight. The jury is still out on
whether Vitamin D2 or D3 is absorbed better. For vegans, obviously the choice
is clear.
How do I get
enough Vitamin D?
Naturally: Our skin will produce vitamin
D3 by exposing it to sunlight without sunscreen. 5 – 10 minutes a day 3 x
week is sufficient to get adequate doses of Vitamin D in your system. I
must warn you of the Skin Cancer Foundation’s recommendations that you don’t go
out in the sun without sunscreen.
(They would rather you just take a pill, thank you)
Foods: It is hard to eat enough foods
to get the levels of D you need. Foods contain, or are fortified
with, the form D2 or D3. You will find D in eggs, fish and fish
oil, fortified dairy products and (dare I say it?) beef liver (ugh) and cheese.
Difficult for those on vegan or low fat diets, but many many foods are
fortified. (D3 is the usual form in supplements, but not all are Vitamin D3)
Supplements: Here is where it gets
tricky…..initially, the RDA (recommended daily allowance) of vitamin D was
thought to be 200 UI/day but we now know that this amount just is not enough.
The consensus from many sources is that every adult should be taking 2000
IU/day.... especially, the elderly, dark skinned people, those who live in
colder climates (don’t get sunlight exposure), over weight (vitamin D is
prevented from absorption in overweight persons) and those who have
inflammatory bowel disease like Crohn’s that affect absorption.
Toxicity: Initially, there was not enough
evidence to put a number on the upper limit for intake of vitamin D. Early
studies showed that abnormally high levels of blood calcium were observed in
those that took in excess of 50,000 IU /day of vitamin D. This led
the Food and Nutrition Board to establish VERY conservative maximum upper
intake levels of 2000 IU/day.
Since 1997,
more and more studies have been done that show vitamin D toxicity is very
unlikely in healthy people at intake levels lower than 10,000 IU/day.
Toxicity can
further be avoided by taking it in conjunction with Vitamin K. When taken with
Vitamin K, vitamin D is less likely to reach toxic levels. Certain
companies are now making Vitamin D with Vitamin K together. Not much info on this, but I’m told by
experts in the field that the data is there, and there will be more supplements
that contain a combo of vitamin D and K in the future.
Be careful
Vitamins are
not regulated by the FDA and because of that there is no guarantee that because
the bottle says “Vitamin D3 1000 IU, that it contains what it states.
Pick a vitamin
company that you trust. Look at their philosophy….look at who owns the
company…. how long have they been around….any claims about certain products
should have data to support it. Call the company and ask questions.
Vitamins lose
their potency so check expiration dates.
Look for a
descriptive label…..does the bottle say just “Vitamin D”…..or Vitamin D3?
Look at the
fillers….yeasts, preservatives….bulking agents, binding agents, etc….
Do they “do
good” for the community? do they donate a portion to research etc?
Bottom line
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