Vitamins, Minerals, and “Supplements”

Whole foods in balance and in moderation are still best

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:

• Whole foods in balance and in moderation are still best.
• Sufficient calcium and vitamin D supplementations of approximately 1,000 milligrams and 800 units daily, respectively.
• Fish oil supplementation is probably of some benefit, but the exact dose is uncertain. Taking it appears to cause no harm.
• 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).
• 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.
• Except for calcium and "vitamin" D (which is actually a hormone, not a vitamin), and folate for women who contemplate becoming pregnant, single vitamins or minerals are likely to be harmful. For example, most studies of vitamins C, A, and E taken in supplement form have shown harm, not benefit. The same is true for single minerals, such as selenium, zinc, chromium, and so on. 

To repeat, except for calcium, folate, vitamin D, and perhaps magnesium, no evidence supports the use of any single vitamin or single mineral supplement. Any reasonable diet contains sufficient magnesium and folate, and probably all necessary minerals as well. (Some disease states are exceptions to these statements, but most of these are rare. Vitamin B12 deficiency is not a rare disease state, but its cause and magnitude should be diagnosed properly by a physician, and never just assumed.)
 
A well-known principle of nutrition science is 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 preparations 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 also in balance, including some 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 the services of a personal trainer.)
 
An important caution is that postmenopausal women and all men should NEVER take either iron supplements or multivitamin/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 postworkout shakes (or bars)? If these contain high-quality, food-based ingredients, they 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 dietitian/nutritionist if you plan to take vitamins, minerals, or supplements.
 
Until sooner,


By Eli Goodman, MD
Medical Insights Blog