Some foods, drinks, lifestyle factors and medications can deplete levels of certain nutrients as well as interfere with their absorption. Here are some steps you can take to protect yourself.
Tea and coffee: Known to interfere with absorption of iron and other minerals, including zinc, magnesium and calcium. Coffee has been shown to reduce iron absorption by up to 80% when drunk within an hour of a meal. Protect yourself: Drink water with meals and to take medications unless otherwise instructed. Take supplements with water or orange juice (often recommended for taking supplements as is contains vitamin C, which converts iron into a more soluble forrm).
Fibre: High fibre diets speed the passage of food through the bowels but may also reduce the amount of minerals absorbed, especially calcium. Protect yourself: If following a high fibre diet, ensure you get enough calcium from milk and dairy products, broccoli, nuts, seeds and pulses.
Antibiotics: These can interfere with the action of vitamin K in the body and can deplete levels of 'friendly' gut bacteria. Tetracycline antibiotics also bind to calcium found in dairy products - which can decrease absorption of both the antibiotic and calcium. Protect yourself: If taking long-term antibiotics (e.g. for acne), increase your intake of vitamin K (found on cauliflower, broccoli, dark green vegetables). After a short-course of antibiotics, it is a good idea to take a probiotic to replenish stores of 'good' bacteria.
ACE inhibitors: Medications used to treat high blood pressure or heart failure are thought to deplete zinc levels and can lead to a zinc deficiency. Protect yourself: If taking ACE inhibitors long term, increase your intake of zinc-rich foods such as red meat, sseafood (especially oysters), offal, whole grains and pulses.
Statins: As well as lowering raised cholesterol levels, statins switch off production of the body chemical, co-enzyme Q10. This reduction is thought to be a contributing factor to many of the side effects associated with statin treatment. Protect yourself: Try a daily coQ10 supplement. A dose of 100mg is recommended.
Corticosteroids: When taken orally long term, these drugs can cause thinning of bones and increase the risk of osteoporosis-associated fractures, partly by reducing calcium absorption in the gut and increasing calcium loss in urine. Protect yourself: Make sure you have good intakes of calcium and vitamin D, which are vital for bone density and to protect against osteoporosis.
Dr Sarah Brewer in Healthspan magazine, Autumn 2014
