St. John's Wort, herbal comfrey, and kava supplements can have serious side effects and should not be taken long term. Dietary supplements can interact with each other, as well as with over-the-counter (OTC) and prescription drugs. Unlike drugs, the U.
S. Food and Drug Administration (FDA) is not authorized to review the safety and effectiveness of dietary supplements before they are marketed. It is up to manufacturers to ensure that their products do not contain contaminants or impurities, are properly labeled, and contain what they claim. Confused? National Institutes of Health (NIH) fact sheets provide detailed information on the benefits and risks of individual vitamins and minerals, as well as herbal supplements.
As an expert in the field of nutrition and health, I'm often asked about dietary supplements. While supplement trends come and go, there are seven supplements that have historically been popular, and in all cases, experts recommend taking them with care, if at all. Vitamin D is essential for a strong skeleton and for calcium absorption in the body. Vitamin D supplements are popular because it's difficult (if not impossible for some) to get enough from food. In addition, our bodies produce vitamin D when bare skin is exposed to direct sunlight, but the increase in time spent indoors and the widespread use of sunscreen have minimized the amount of vitamin D that many of us get from exposure to the sun.
However, vitamin D supplements are a sensitive topic. Sometimes, guidelines and research may seem to contradict each other. The truth is that enthusiasm for vitamin D supplements is outpacing the evidence. And high doses aren't a good option. In healthy people, vitamin D blood levels greater than 100 nanograms per milliliter can cause additional calcium absorption and cause muscle pain, mood disorders, abdominal pain and kidney stones, notes the Cleveland Clinic.
It can also increase the risk of heart attack and stroke. That said, vitamin D supplements may benefit certain people, including those at risk of a deficiency, such as people with darker skin, certain health conditions and older adults. The most recent consensus statement from the American Geriatrics Society specifically suggests that people over 65 can help reduce the risk of fractures and falls if they supplement their diet with at least 1000 IU of vitamin D per day, in addition to taking calcium supplements and eating foods rich in vitamin D. Keep in mind that vitamin D supplements and medications can interact with each other. St. John's Wort is a plant that is used as tea or in capsules, with supposed benefits for depression, attention deficit hyperactivity disorder, menopausal symptoms, insomnia, kidney and lung problems, obsessive-compulsive disorder, wound healing and more.
John's Wort will be effective in treating mild depression; however its interaction with medications should be taken into consideration. John's Wort may reduce the effectiveness of other medications such as birth control pills, chemotherapy drugs against HIV or AIDS, and medications to prevent organ rejection after a transplant. Calcium is essential for a strong skeleton but too much of this mineral can be harmful. More than 2500 mg per day for adults ages 19 to 50 and more than 2000 mg per day for people age 51 and older can cause problems. Calcium supplements carry risks such as hardening of the arteries or atherosclerosis and an increased risk of heart disease; however research is conflicting on this matter.
The Dietary Guidelines for Americans suggest several dietary sources of calcium such as plain low-fat yogurt, tofu, skim milk, cheese, fortified cereals and juices. Kava supplements can damage the liver; therefore it should not be taken long term without consulting a doctor first. Herbal comfrey has been linked to liver damage; therefore it should be avoided altogether. As an expert in nutrition and health I always recommend taking dietary supplements with care - if at all - due to their potential side effects or interactions with other medications or supplements you may be taking. Before adding any new supplement to your regimen it's important to talk to your health care team if you're managing an underlying health condition (especially if you're taking medications) or are pregnant or breastfeeding.