In every grocery cart across America, one can easily find some form of dietary supplement. A substantial number of American adults now take one or more dietary supplements to either prevent or treat a variety of conditions. U.S. consumers spend approximately $14.8 billion a year out-of-pocket, about one-third of the amount that is spent on prescription drugs. There are many common dietary supplements with the most popular including probiotics, echinacea, fiber, ginger, ginseng, glucosamine, minerals, omega-3 fatty acids (fish oil), St. John ’s Wort, saw palmetto, vitamins and minerals.
What is a dietary supplement?
According to the Dietary Supplement Health and Education Act passed by Congress in 1994, dietary supplements are legally defined as a product other than tobacco that is:
1) Intended to be added to one’s diet
2) Contains one or more of either a vitamin, mineral, herb, botanical, amino acid , or bacteria ( probiotics)
3) Intended to be taken by mouth
4) Labeled as being a dietary supplement
Dietary ingredients sold before October 15, 1994 — the date the law was enacted — do not require specific safety information whereas any new dietary ingredient after this date requires specific safety information labels approved by the US Federal drug Agency. This is important because supplements are not as tightly regulated as prescription drugs and products used before that date do not require any special warnings.
How useful are supplements?
For most Americans if you are not eating a nutritious variety of foods, supplements may help get that adequate amount of essential nutrients. For example, calcium and vitamin D are very important for keeping bones strong and reducing bone loss and therefore often needs to be supplement especially in postmenopausal women and those with osteoporosis. Folic acid may need to be supplemented in women to decrease the risk of certain birth defects. Omega-3 fatty acids found in fish oils may help some with heart disease. Probiotics, an increasingly popular supplement otherwise known as “good bacteria,” may help conditions like diarrhea associated with using antibiotics and irritable bowel syndrome. Daily multivitamins may help to prevent certain types of cancer.
Safety and Risks
Although most supplements are safe, some may cause side effects or harm when taken instead of prescribed medicines or taken in combination with prescription medicines without letting your doctor know. For instance, vitamin K can reduce the ability of a blood thinner, warfarin, to prevent blood from clotting. St. John’s Wort can speed the breakdown of many drugs, including antidepressants, birth control pills, seizure drugs and antiretrovirals used in HIV treatment and thereby reduce their effectiveness. Antioxidant supplements like vitamin C and E might reduce the effectiveness of some types of cancer chemotherapy.
Five Important tips about Supplements
- Always be an informed consumer. If a claim about a supplement sounds too good to be true — it probably is. This is especially true when a product claims to treat or help erectile dysfunction, weight loss, body building, pain control and other highly personal conditions in which people are embarrassed to ask questions or just desperate to get relief.
- Just because something is labeled as “natural” does not necessarily mean it is safe. Some botanicals or vitamins can lead to serious medical problems especially if they are taken in excess. Too much vitamin A, iron, and vitamin B6 can hurt you. Ephedra, a product sometimes found in weight loss supplements, can increase the risk of strokes and other problems when too much is ingested. Some products may have fillers or contaminants.
- Always talk to your healthcare provider and tell them about any products you use so as to avoid any serious drug interactions with prescription drugs.
- Don’t assume that dietary supplements are as safe as prescription drugs. Be as careful about supplements as you would with any pill you would take from a doctor.
Dr. Joseph Sirven is a first-generation Cuban-American. He is Professor and Chairman of the Department of Neurology and was past Director of Education for Mayo Clinic Arizona. He is editor-in-chief of epilepsy.com and has served US and global governmental agencies including the Institute of Medicine, NASA, FAA, NIH and CDC.