Iron, Omega-3 and Calcium Supplements.. Doctor’s Advice on the Right Way to Take Them

The time of day is generally less important than taking supplements consistently and in a way that supports absorption. Fat-soluble vitamins such as vitamins A, D, E and K are better absorbed when taken with a meal containing some dietary fat. Water-soluble vitamins such as B-complex and vitamin C can generally be taken with water.

Iron is usually absorbed better when taken on an empty stomach. However, it may cause nausea, stomach pain or constipation in some people. If these problems occur, taking it with a small amount of food may make it easier to tolerate. Tea, coffee and calcium can interfere with iron absorption, while vitamin C can help improve absorption. People taking thyroid medicines such as levothyroxine should maintain an appropriate gap from iron supplements.

Omega-3 fish oil supplements are best taken with a meal containing some fat, which can improve absorption and may reduce unpleasant fishy aftertaste or burping. Calcium and iron should generally be taken separately because calcium can reduce iron absorption. The exact dose and timing should depend on the supplement, individual needs and medical advice.

Note: Do not start multiple supplements or high doses without medical advice. People taking supplements for a prolonged period, or those with conditions affecting blood, digestion, liver or kidneys, may need appropriate blood tests to identify actual deficiencies.