Some Comments on Vitamins, Minerals & "Supplements"
Nutritious food that is properly prepared, in balance, and consumed in moderation remains the only guaranteed "best program" for optimal nutrition. The science of nutritional supplements, deficiencies, vitamins, minerals, etc, remains challenging. Controlled studies, including outcomes studies (i.e. those that determine if an intervention really helps us or not), are difficult to do because there are so many variables. Evidence-based guidelines are sparse.
Medical science currently recommends the following in terms of vitamins, minerals, and supplements:
1) Whole foods in balance and in moderation are still best .
2) Sufficent calcium and vitamin D supplementations. Approximately 1000mg and 800 units daily respectively.
3) Fish oil supplementation is probably of some benefit, but the exact dose is uncertain. There appears to be no harm to take it.
4) Multiple vitamins/minerals-- MAYBE!! We still do not know if these are either truly beneficial or perhaps harmful. If taken, these supplements should be complete and in balance, avoiding excess doses of any component(s).
5) Protein supplements, even those derived from high quality foods such as whey, and even those that contain all the essential amino acids, are NOT better than regular food-derived protein. Also supplements are much more expensive on a gram per gram basis than is regular food. Eggs, milk, meat (even the most expensive cuts), fish, beans, etc, are better and cheaper sources of protein than any supplement
product. Too much protein can be harmful.
6) Except for calcium and "vitamin" D (which is actually a hormone, not a vitamin), (and folate for women who contemplate to become pregnant), single vitamins or minerals are likely to be harmful. For example, most studies of vitamins C, A, & E taken in supplement form have shown harm, not benefit. The same is true for single minerals, such as selenium, zinc, chromium, etc.
To repeat, except for calcium, folate, "vitamin" D, and perhaps magnesium, there is no evidence to support the use of any single vitamin or single mineral supplement; noting, again, that any reasonable diet contains sufficient magnesium and folate; and probably all necessary minerals as well. (There are some disease states that are exceptions to these statements, but most of these are rare. B12 deficiency is a disease state that is not rare, but its cause and magnitude should be diagnosed properly by a physician, and never just assumed.)
There is a well known principle in nutrition science that vitamins must be taken in balance. If any are taken in excess, then relative deficiencies of others might occur. If one looks at the proprietary multivitamin/mineral preps on the market, most are wildly out of balance-- too much of this, too little of that. Very few are in reasonable balance. One that is, and that is probably reasonable to take, is the "One-A-Day Energy" brand. Not bad, although it does have a small amount of iron. "Shaklee" makes a couple of preps that are in balance also, including preps without iron. (The Shaklee supplements are expensive, however. One would do better to use the money to buy good foods, a health club membership, and/or to help pay for a personal trainer.)
An important caution is that post menopausal women and all men should NEVER take either iron supplements or multivit/mineral preps that have iron; unless diagnosed with true iron deficiency-- in which case they should take iron by prescription. Too much iron, even in small doses, can be quite harmful.
As for meal replacement shakes (or bars) and post workout shakes (or bars): if these contain high quality food-based ingredients, these are fine-- but no more than once a day. I still personally prefer and recommend regular food.
The above guidelines should be helpful, but keep in mind that nutritional science is complex. Most claims about the benefits of this or that supplement product are either unfounded or false. Nutritional requirements change with normal age-related physiologic changes. They change even more so in the presence of disease. Thus, it is best to consult your physician or a registered dietician/nutritionist if you contemplate to take vitamins, minerals, or supplements.
Eli Goodman, MD
(This piece appeared several years ago on the senior citizens resource website: SilverPlanet.com.)