What
Vitamins Should I Take Doctor?
Published April 6, 2002 in the North
Island Weekender
We can answer this question with a much more informed answer now than we could ten
years ago. Considerable new research both clinical and experimental has given
us this information.
Folic acid we all know now, if at low levels before and during pregnancy and
during significantly increases the risk of various types of birth defects including
the most common, neural tube defect.
There is also an association of low levels of folic acid and an
increased risk of heart disease, stroke, diabetes, arthritis and bone mineral
metabolism. 20% of the population has a deficiency of an enzyme MTHFR that
makes them less responsive to folate in their diet. Some people are also poor
absorbers of folate in the gut so there is a decrease of folic acid absorption
across the gastrointestinal membrane. This nutrient is certainly on the list
and the evidence exists that supplemental folate appears to be preferable to a
food form, in increasing the levels of plasma folate and improving physiologic
function. If someone says food sources of a nutrient is always preferable to
supplements, this is a case where the evidence suggests that supplemental folic
acid and its various forms are preferable to food sources. High serum folic
acid levels are associated with lower risk of colon and breast cancer. Dosages
may vary depending on the individuality of the person, 400mcg may be enough to
keep the homocysteine (see my Dec 29, 2001 article
on heart disease) levels within normal limits, but dosages much higher than
that may be required to reduce the risk of cancer, especially in someone who
has a decreased MTHFR enzyme.
Vitamin B6 has an RDA of 2mg! If dietary intake falls below this there is an
increase in coronary heart disease. Meats and legumes are the major sources of
B6 and as people decrease their intake of meat they need to increase their
intake of legumes to make sure they are getting enough B6. A multivitamin will
typically give you up to 50- 100 mg per pill, which is very adequate for
prevention of heart disease.
Vitamin B12 is decreased in the elderly who have reduced absorption due to
decreased stomach acid and elevated homocysteine is found in this population.
Similarly those who are taking acid suppressing drugs also have lowered serum
B12 levels. 12% of the elderly may have inadequate B12 stores and this marginal
B12 status may have neurological implications causing depression and cognitive
dysfunction. So in this population B12 supplementation may be desirable. The
form of B12 in a multivitamin does not require gastric acid for absorption so a
multivitamin can ensure adequate intake and is preferable to the food form.
Vitamin A is the number one of the fat soluble vitamins. It is often thought to
be the same as beta-carotene and carotenoids, but these are precursors to
Vitamin A that need to be cleaved by certain enzymes to form retinal, or
Vitamin A. We used to say that as long as you ate enough dark red and orange
vegetables that you were getting enough Vitamin A, or in other words “Eat your
carrots, it is good for your eyes”. However now it is recognized that Vitamin A
doesn’t always get delivered due to the uniqueness of a person’s metabolism and
it is more than a vision related nutrient. It is found in its metabolic form as
all-trans-retinoic acid and is a very important in binding retinoid receptors
and Vitamin D metabolites to regulate gene expression. This metabolite is
important in messaging between cells and preventing some forms of cancer and
for proper cell differentiation of cells for healthy aging. Vitamin A is a
problem nutrient in many individuals and supplementation of both vitamin A and
carotenes may be important.
This discussion about the article “What vitamins should I take doctor” found in
the December 20th 2001 issue of the New England Journal of Medicine will
continue to include vitamin D, vitamin C and vitamin E.
Dr. Pincott has been practicing naturopathic
medicine since 1985 and is currently practicing in Campbell River. She can be
reached at (250) 286-3655 or www.DrPincott.com