Are supplements worth taking?

Supplements often come in tablet or capsule form and typically refer to vitamins or minerals but may also include other components of foods such as herbs and plant materials such as ginseng, garlic, and green tea.

Despite the promises made by some manufacturers, the recommendations from World Cancer Research Fund UK (WCRF UK) is to not take supplements to protect against cancer and to instead meet nutritional needs through diet alone. Some supplements can actually increase cancer risk. For example, beta carotene was found to increase risk of lung cancer in smokers.

Most people can meet their nutritional needs by eating a healthy, balanced diet but there are some groups that may benefit from taking supplements. The NHS recommends that if you're pregnant, trying for a baby or could get pregnant, you should take a 400 microgram folic acid supplement every day until you're 12 weeks pregnant. Folic acid supplements need to be taken before you get pregnant, so start taking them before you stop using contraception or if there's a chance you might get pregnant. Folic acid can help to prevent neural tube defects such as spina bifida.

The NHS also recommends that children aged 6 months to 5 years should take vitamin supplements containing vitamins A, C and D every day. A GP may also recommend supplements if you need them for a medical condition. For example, you may be prescribed iron supplements to treat iron deficiency anaemia.

Some evidence suggests that we should be supplementing with vitamin D during the winter months. Vitamin D is one of the two vitamins we can’t get enough of through diet alone. Vitamin D is made when we are exposed to sunlight and while some vitamin D is added to milk, not enough to meet our requirements and so we may need to take vitamin D supplements.

The only other vitamin not made by plants is vitamin B12. It’s made by bacteria that cover the earth and grow in the guts of some of the animals people eat, and so their bodies can be sources of B12 for those eating animals. We likely used to get all the B12 we needed drinking out of streams or wells but now we chlorinate our water supply to kill off any bacteria, so we don’t get a lot of B12 in our water anymore. But in our sanitized modern world, those eating plant-based diets are simply not getting enough vitamin B12.

Vitamin B12 is necessary for keeping your nerves healthy and supporting the production of DNA and red blood cells, as well as maintaining normal brain function. A B12 deficiency can happen if you have a vegan diet and do not take vitamin B12 supplements or eat foods fortified with vitamin B12 such as nutritional yeast fortified with B12.