Frequently Asked Questions
Should I take vitamins and other nutritional supplements?
I often recommend that people take a high-quality multivitamin to
ensure that they get enough vitamin D, B12, zinc, iodine, and sele-
nium. Very few individuals eat perfectly, and some of us requiremore of certain nutrients than others. It makes sense to be sure that
you ingest adequate amounts of all these important substances. I also
recommend a sensibly designed multi because I instruct my patients
to avoid salt. Salt is iodinated, making it the primary source of iodine
in most people's diets; therefore, a multi can ensure adequate iodine
intake for those who avoid salt in their diet.The main concern with taking a multivitamin is that it may
contain a high dose of vitamin A or beta-carotene. Ingesting large
amounts of these nutrients may interfere with the absorption of other
carotenoids, such as lutein and lycopene, thus potentially increasing
the risk of cancer.^1 There is also concern that supplemental vitamin A
induces calcium loss in the urine, contributing to osteoporosis. Even
though too much vitamin A is known to be toxic to the liver, the
most common effect of toxic doses of vitamin A in animals is sponta-
neous fracture. Apparently, excessive vitamin A is potentially a prob-
lem in humans, too — one study comparing vitamin A intake in the- 5 mg range to the 1.5 mg range showed a doubling of the hip frac-
ture rate.^2 There are multiple vitamins available today with natural,
mixed carotenoids in place of vitamin A and beta-carotene that also