By Karin Boode, PhD
Last week we discussed vitamin K, which is the last in the series of fat-soluble vitamins. Before we continue with water-soluble vitamins I will discuss vitamin supplements with you. Every year we are spending over 20 billion dollars on vitamin supplements. Studies have shown that more than half of American adults take at least one dietary supplement. But despite their popularity, many experts remain skeptical of their impact. It is believed by many that using vitamin supplements ensures that you will stay healthy. What they don’t realize is that water-soluble vitamins (B and C vitamins) are either used right away or leave the body unused. They do not get stored. Eating large doses is therefore, not accomplishing the desired result.
Fat-soluble vitamins (A,D,E and K vitamins) that are not used immediately by your body are stored in the liver. As a result stockpiling of this type of vitamin can be toxic.
Does this mean that you should not take vitamin supplements? The debate surrounding this question continues, fueled by staunch advocates of both positions. On the one hand, conservatives may dismiss anyone who suggests a need for vitamin supplements. On the other hand, self-proclaimed “experts” may push megadoses of everything from vitamin A to zinc. However, the truth lies somewhere in the middle. Large doses of vitamins are not the answer, but completely staying away from vitamin supplements is not necessarily the right approach either.
What exactly is a dietary supplement? As defined by Congress in the Dietary Supplement Health and Education Act, which became law in 1994, a dietary supplement is a product that
- is intended to supplement the diet
- contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances) or their constituents;
- is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and
- is labeled on the front panel as being a dietary supplement.
Dietary supplements are regulated by the FDA as foods, but the rules for vitamin supplements are different than for other foods and drugs. Vitamin supplements may NOT have a claim on the label that their product will diagnose, cure, treat or prevent a disease. It may contain one of three types of claims:
- a health claim, describing the relationship between the vitamin supplement and risk reduction of a health-related condition
- a nutrient content claim, describing the relative amount of a nutrient in a product
- a structure/function claim, describing how a product may affect the organs or systems of the body, without mentioning a specific disease. If this type of claim is on the label it must also state “This statement has not been evaluated by the FDA. This product is not intended to diagnose, cure, or prevent any disease”.
Vitamin supplement production has not been standardized in the US. If you find the word “standardized” on the label, it can simply mean that the same recipe is used at all times. Even if this is the case, that is not a guarantee for quality of the supplement.
Recommended Daily Allowances (RDA) exist for vitamins, but this is only a general guideline. The need for vitamins varies by individual, depending on age, lifestyle, diet and diseases. It is always safest to consult your primary care physician before using any supplements.
Healthy Habits for Vitamin Supplements:
- Read the labels carefully. Even though the regulations for vitamin supplements are not as strict as for other foods and drugs, all the claims and information that are on the label have to be accurate. Use the information to make a more informed decision.
- Vitamins, like drugs, can be harmful in large amounts. Many foods these days are fortified. You may be getting more of a specific vitamin in your diet than you realize.
- Discuss your vitamin intake with your primary care provider to make sure that your needs are the basis for supplementing vitamins.
- All nutrients work together to promote good health. Consuming large amounts of one vitamin may induce defiencies of other vitamins or nutrients
- Food is the best source of nutrients, including vitamins. Follow the healthy habits that we provide for each vitamin. If you do so, your need for vitamin supplements should be limited.