Side Effects of Megavitamins

Vitamins are an important component of overall good health. The Food and Drug Administration (FDA) branch of the government sets and publishes the standard recommended daily requirements for vitamins and minerals. The FDA advises that the best way to get the necessary vitamins is through natural food sources, and supplementation is not necessary for the majority of individuals who consume a healthy diet. Megavitamins are dosages of vitamins that far exceed the daily recommended dietary allowance (RDA).

Therapeutic Claims

• Megavitamin therapy is controversial in the United States. Proponents of this type of alternative treatment have been asserting the health value of megavitamins for overcoming illness for more than 50 years, regardless of numerous warnings by the FDA of toxicity caused by excessive vitamin intake above the recommended daily allowance. Orthomolecular medicine is another term for megavitamin therapy.

Risks

• Certain vitamins pose a risk when taken in large amounts; however, others do not have a known toxicity level. Excess amounts of the water-soluble vitamins are normally cleared from the body through the kidneys, except for vitamin B-12, which is stored in the liver. The fat-soluble vitamins normally pose a higher risk of toxicity due to the fact that the body stores them in the liver and fatty tissues. Symptoms of vitamin toxicity range from mild to serious.

Toxicity Symptoms

• High doses of vitamin A have been known to cause a range of effects from mild headaches to seizures. Recent findings suggest that too much of this vitamin can promote osteoporosis
  Too much vitamin D has been shown to cause muscle weakness, vomiting and cardiac arrhythmias.
  Large amounts of B vitamins can slow blood flow, causing hypotension and numbness.
  Vitamin C in high doses may cause vomiting and diarrhea, as well as increased levels of estrogen.

Theories/Speculation

• High doses of vitamins may be part of an alternative treatment meant to prevent disease. There are many claims that certain vitamins can cure or prevent some illnesses; however, the general consensus of the scientific health community is there are no legitimate studies to support these claims.

Considerations

• Vitamins are necessary for health and are found in their natural state in many food sources. Some individuals may require supplementation of certain vitamins. People with digestive disorders don't always absorb the necessary amount of vitamins from their diet. Pregnant and lactating mothers often need additional vitamins in order to ensure optimum health for themselves and their infants. Some medical conditions may make vitamin supplementation necessary. Individuals should consult with their health practitioner before undertaking any health program that involves taking mega doses of vitamins or minerals.