Nutritional/dietary supplements are products intended to supplement one's diet and can contain vitamins, minerals, herbs, amino acids, or other ingredients. The Dietary Supplement Health and Education Act defines supplements and regulates them differently than foods or drugs. Supplements come in various forms like tablets or powders. Some supplements like calcium and vitamin D are effective for bone and heart health, while the effectiveness of others requires more research. Supplements can interact with medications and cause side effects, so they should be taken carefully and under a doctor's supervision.