Caution on Dietary Supplements

If you have read previous postings (Aug 11, Aug 29, and Nov 7, 2011, Feb 10 and 27, 2012), you might think that I have a negative view of dietary supplements:  vitamins, minerals, herbs and the like.  Actually, my concern is that people are too easily persuaded of their efficacy and too casual about potential dangers.

First it’s a discipline issue – just another shortcut.  Eat anything you like but take your vitamins.  Some promoters promise that you will magically avoid disease or old age.  Friends and relatives swear by their power and offer free samples at home or at work.  Few of these people have researched the science behind them, so it’s impossible to separate real results from the placebo (sugar pill) effect.  To make matters worse, FDA regulation of these substances is far more lax than for prescription medication, and we all know stories where the FDA had to backpedal on well-tested drugs.

I was reminded of this by three recent news articles in quick succession.  “Omega-3 supplements may not aid aging brain” (June 14).  This comes at a time when many foods have added to their labels “with omega-3” as if it were some wonder drug.  “Task force recommends against Vitamin D, calcium supplements” for preventing cancer or bone fractures (June 14).  Contrast that with news the next day “Vitamin D With Calcium Shown to Reduce Mortality in Elderly.”  Further in this article it warns, "Some studies have suggested calcium (with or without vitamin D) supplements can have adverse effects on cardiovascular health…Although our study does not rule out such effects, we found that calcium with vitamin D supplementation to elderly participants is overall not harmful to survival, and may have beneficial effects on general health."  (I added the emphasis to show how iffy these conclusions are.)  No wonder people are confused and more apt to take the advice of a neighbor or co-worker!

Furthermore, in the case of supplements the government is less involved, leaving the responsibility for understanding benefit and side effects to us.  FDA guidelines on supplements generally show that they get involved in problems or safety issues only after they arise.  It is the manufacturer’s responsibility to ensure safety.  There are no regulations regarding dosage, and if they advertise benefits that are not true, it becomes a case for the Federal Trade Commission (FTC) to prove that they are making false promises.

In terms of discipline and critical thinking then, the wisdom when it comes to supplements is three-fold.  First, it is better to get needed nutrients from your food than from a pill, vitamin water or an additive to some convenience food – calcium from dairy and vitamin D from the sun, etc.

Second, it’s smart to be skeptical about claims of manufacturers and your friends.  As you can see the research is still going on, even on basic items such as calcium supplements for bone loss, and tests are not always as stringent.  It takes some research to separate the claims from reality. 

Finally, it’s best to consult with your doctors, as supplements do have side effects and may interact either with each other or with prescription drugs.