Folic acid supplements not always of benefit

Taking folic acid supplements in early pregnancy plays an important role in preventing spina bifida. There are some health conditions in which folic acid also has some benefits, but experts warn that its role in cancer is unclear.

Writing in the April edition of Australian Prescriber, rheumatologists Dr Serena Parker, Dr Patrick Hanrahan and Dr Claire Barrett say that there is no clear evidence that folic acid supplements in the general population reduce the risk of heart disease, dementia or cancer. In fact, there may be evidence that they increase the risk of cancer. 

Folic acid is an important B vitamin found in green leafy vegetables. It is needed for making and repairing DNA, write the authors.

The Australian Government recommends that all pregnant women take a folic acid supplement of at least 400 microgram/day and also aim for a dietary intake of 600 microgram.

Folic acid supplementation should ideally begin one month before conception and be maintained for at least three months afterwards.

There is also clear evidence that the routine use of folic acid can reduce the risk of some adverse effects in patients taking methotrexate for rheumatoid arthritis.

However, the authors say that taking folic acid for heart disease or dementia has not been shown to have any benefit. There is also conflicting evidence about cancer prevention.

“There is no evidence that folic acid supplementation reduces the risk of colorectal, breast or prostate cancer,” write the authors.

"Some reported studies suggest an increased risk of breast, prostate, colorectal and endometrial cancer."

Apart from pregnancy and treatment with methotrexate, most people with a healthy diet should not need to take folic acid supplements.

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