When you ask your patients to tell you about the supplements, there’s a good chance you will hear something like this: “Dr. Oz says he takes (fill in the name) supplement. It’s supposed to be great for (fill in the benefit) and prevents (fill in the disease).” It’s important to pay attention to what supplements are popular and to learn a little bit about each one. How a supplement works, what is the proper dose, as well as side effects and drug interactions can affect the patient’s health, both now and long-term.Let’s look at five popular supplements that your patients may be taking:1. Fish oils. About 10% of Americans take a fish oil supplement. Recent research has left experts split on whether the omega-3 fatty acids from capsules are effective. Fish oil contains EPA, which has anti-inflammatory benefits, thought to be useful for heart and brain health, as well as conditions such as arthritis. Patients should know that fish oil in large doses can prevent blood platelets from clotting, thus working as a blood thinner. If your patient is not eating fish three times a week, a daily teaspoon of high-quality cod liver oil is likely safe, until scientists agree on the value of this popular supplement.2. Multivitamins. You wouldn’t think there is anything wrong with taking a daily multivitamin pill, but patients should choose wisely. Because 15% of menstruating women are anemic, those under age 50 should take one with iron, along with folic acid (dose < 1000mcg) to prevent neural tube defects in their babies. Women over age 50 and all adult men should avoid iron supplements and keep folic acid at 400mcg. Be aware that credible studies have shown that multivitamins do not affect coronary disease outcomes or prevent cancer.3. Vitamin D. The prestigious National Health and Nutrition Examination Survey (NHANES) estimates that 66% of Americans have a vitamin D deficiency. Low vitamin D levels have been implicated in dementia, prostate cancer, type 2 diabetes, heart disease, and schizophrenia. Low levels of vitamin D in a child’s first ten years have been shown to correspond with a greater risk of multiple sclerosis. When possible, a 25-hydroxy blood test is the most accurate way to check for a normal result in the 20-50ng/mL range. Experts disagree on what is the optimal level. Sunshine is the best way to obtain vitamin D; ten minutes of summer sun on bare arms and legs is sufficient. In winter, many people need to rely on supplements or eat salmon 2-3 times a week.4. Coenzyme Q10. A natural antioxidant made by the human body, Coenzyme Q10 (CoQ10) is necessary for cell function. Tissues with a high energy requirement have a need for increased CoQ10. Patients with diabetes, cancer, Parkinson’s disease, and multiple sclerosis require extra CoQ10, as well as patients who are on statin therapy for high cholesterol. CoQ10 levels drop as people age, so supplements may be useful to increase energy levels as the body produces ATP from cellular processes. As with other supplements, Coenzyme Q10 is not a short-term solution. It must be taken long-term to sustain any benefits.5. Calcium. Although nutrition surveys show that Americans come close to meeting the daily calcium requirement, both men and women fall short, making calcium one of the most popular supplements. Calcium is necessary for maintaining bone structure, especially in post-menopausal women. But it’s also helps keep blood pressure at a healthy level, as well as preventing some cancers. Calcium intake tends to decrease with age, so supplements can be useful, especially when combined with vitamin D. Remind your patients that calcium supplements are best absorbed when taken in smaller doses throughout the day, usually with food.Take time to ask about the supplements your patients are taking and then document on the health record. Despite controversy and unproven health claims, dietary supplements are here to stay. And many do have benefits. The only question: Which will be the next popular supplement?