Since most people's diets are not ideal and individual absorption and utilization varies from person to person, it makes sense to recommend that all people take a high-quality multiple to assure most favorable vitamin D, B12, zinc, iodine, and selenium status, to name a few.

Even if your diet is ideal, some people require more of certain nutrients than others. For example, it is not uncommon for some people to need extra vitamin D, or extra B12, even when their diets contain typical amounts of these vitamins. This is especially true regarding vitamin D because of the depletion of the atmosphere's ozone layer and subsequent increase in skin damage from the sun. Because of this, many people practice sun avoidance and wear sunscreen, which decreases their vitamin D production.

For many people in America who are not obtaining regular sunshine a multivitamin still may not be enough Vitamin D. Taking an extra vitamin D supplement is advisable if you are one of these people. You could also have your vitamin D level checked with a blood test to make sure yours is adequate.

Since I recommend avoiding all salt added to food there is a legitimate concern that the residual iodine in most soils and therefore our food supply could be insufficient for optimal health. Salt is iodinated, which makes it the primary source of iodine in most people's diets. Therefore, a multiple will assure adequate iodine intake in those who avoid adding salt to their diet.
Dramatically reducing the quantity of animal products in favor of beans, vegetables, seeds, nuts and fruit has the potential to dramatically extend lifespan due to high phytochemcal exposure, at the expense of exposure to Vitamin B12. For many people who are vegans, vegetarians and flexitarians, the small amount of animal products consumed cannot guarantee optimal levels of Vitamin B12, so in these cases a multi-vitamin or a B12 supplement is important. Likewise, a supplement of DHA fat may benefit those not regularly consuming fish.

The judicious use of supplements can be utilized to offer nutritional insurance and protection as well as better assure ideal levels of some difficult to obtain nutrients, but many nutritional supplements cause more harm then good. Remember more is not always better. Almost daily, I see people placing themselves at increased health risk from supplement excess; too much Vitamin A, too much B6, too much beta carotene, too much iron, too much selenium, too much fish oil, too many herbal concoctions and laxatives (called bowel cleansers). People can easily hurt themselves with too much supplementation. We want to supplement intelligently and not incur the risks of excessive nutrients. With many nutrients, too much can be just as bad as too little.

The crucial point that cannot be emphasized enough is that supplements are no substitute for a healthy diet. To the extent they offer some people the confidence to eat less wholesome vegetation; they are hurtful, not helpful. {Please see my vitamin advisor for my general supplemental recommendations.}