Synthetic thyroid hormone supplementation increases calcium loss, reduced bone density and increased risk of osteoporosis. A study from Pennington Biomedical Research Center in Baton Rouge, LA, shows that taking synthetic thyroid accelerates bone turnover and that new bone formation does not offset the loss (Thyroid 2003 Apr;13(4):357-64). Synthetic thyroid can also bind with iron, resulting in anemia and fatigue. Other signs of low iron: hair loss, lowered immune system and brittle nails. Most practitioners don’t recommend supplementing with iron until laboratory testing is done to confirm an iron deficiency.

Drugs often interact with foods. For example, the sulfur compounds in onions, garlic and broccoli encourage the liver to produce detoxification enzymes. These enzymes can speed clearance of drugs from the body. Dark, green leafy vegetables such as collards, kale and turnip greens contain Vitamin K which can interfere with blood-thinners taken to reduce the risk of stroke or heart attack. And grapefruit significantly inhibits the metabolism of about 40% of all prescription medications including calcium channel blockers, cholesterol medications, estrogen, oral contraceptives, some psychiatric medications and most allergy medications.

Orange juice and milk both interact with antacids, increasing the absorption of aluminum into the bloodstream. High fiber foods such as oatmeal can decrease the absorption of some medications. Caffeinated beverages mixed with asthma medication can cause nervousness and excitability.

Consult your pharmacist to find out if your medication can be taken with food or should be taken on an empty stomach.

While most supplements are safe at recommended levels, you should be cautious if you are pregnant or lactating, extremely ill, elderly or on multiple prescription medications. Also seek knowledgeable advice when giving supplements or medications to young children.

In most cases, dietary supplements need sufficient time to work and may take several weeks or months to achieve optimal effects or rebuild reduced nutrient stores.  Always let your physician or health care provider know which dietary supplements you take. Experts often recommend that you stop all supplements at least two weeks prior to surgery.

Educating yourself about your medications and supplements is a wise policy. Become an informed consumer.