Test Your Knowledge

In the United States and other industrialized nations, eating a balanced diet provides sufficient vitamins for most people. This diet should follow the recommendations of the food guide pyramid and include servings of:

• Fruits and vegetables
• Whole grains
• Legumes (e.g., peas, beans and nuts)
• Animal products (e.g., meats, eggs, dairy products)
• Enriched foods and fortified foods (e.g., cereals, pastas, fruit juices)

While these food groups contain significant amounts of vitamins, many factors may reduce the amount the body can use. The bioavailability of vitamins can be changed by how the food is processed or cooked, its freshness and other foods consumed at the same time.

While most people are able to get sufficient vitamins from dietary sources, supplements are commonly used. A study by the U.S. Centers for Disease Control and Prevention (CDC) found they are taken by approximately 40 percent of Americans. While this behavior may be unnecessary and potentially harmful for some people, supplements are likely to improve the health of some groups. People who might benefit from supplement use include:

• Elderly. The body’s ability to absorb many vitamins diminishes with age. This problem can be exacerbated by poor diets that may be consumed by elderly people.

  

• Pregnant and breastfeeding women. Expecting and lactating women need additional nutrients to support the developing fetus and growing newborn. Still overdoses of some vitamins are known to cause a number of birth defects and infant development, so using any supplement should be discussed with a physician.
  
  
• Vegetarians and vegans. People who do not consume any animal products have limited or no natural sources for some vitamins (e.g., B12). Non-animal options to meet the body’s needs include supplements and fortified and enriched foods.

While they may be useful for some people, there are risks associated with supplement use. Most cases of vitamin overdoses, especially among children, are related to supplement use. They also do not provide the carbohydrates, fiber and other beneficial nutrients found in vitamin-rich foods, which can lead to malnutrition. Due to the potential risks associated with vitamin overdoses, supplements should only be used with the guidance of a physician.

Vitamin supplements also may not always contain the ingredients advertised. One recent study of various multivitamin products found that more than half of the supplements evaluated did not contain ingredients in the stated amounts. In addition, many of these products contained lead or failed to break apart properly once inside the digestive tract.