Vitamins and other food supplements taken by millions of women may actually put them at more risk, according to a major study.

最新研究表明，数百万女性经常服用的维生素及膳食补充制剂很可能有害健康。

Scientists say there is little evidence the pills do any good – and in fact some could be causing serious harm.

A study involving nearly 39,000 women has found multivitamins, vitamin B, folic acid, iron, magnesium¹ and copper² all increased the statistical³ risk of premature⁴ death.

Nearly a third of adults in Britain take some form of dietary supplement most days and the industry is worth £675million a year.

Some of the most popular pills include multivitamins, vitamin A, C and E, iron, folic acid and calcium⁵ – which are all thought to improve long-term health and ward⁶ off（避开） illnesses.

Scientists from Finland, Norway, the U.S. and South Korea looked at the long-term health effects of common vitamin pills and minerals on 38,772 women aged⁷ 55 to 69.

Over an 18-year period the women recorded any supplements they regularly took.

The results, published in the Archives of Internal Medicine, found copper increased the risk of dying prematurely⁸ by 18 per cent. Folic acid – which pregnant women are told to take to protect their child against spina bifida（脊柱裂） – increased risk of death by almost 6 per cent, while iron raised the risk by nearly 4 per cent.

Multivitamins raised the risk by 2.4 per cent, vitamin B6 by 4 per cent, magnesium（镁） by 3.6 per cent and zinc⁹ by 3 per cent.

The scientists do not fully¹⁰ understand how supplements may trigger early death, but they may interfere¹¹ with the body’s natural defences. They say the supplements should only be taken by patients who are malnourished and only under the supervision¹² of a doctor. Everyone else should ensure they eat a balanced diet to get adequate vitamins and minerals.

Jaakko Mursu, from the University of Eastern Finland, said: ‘Based on existing evidence, we see little justification¹³ for the general and widespread use of dietary supplements.

‘We recommend that they be used with strong medically-based cause, such as symptomatic nutrient¹⁴ deficiency disease.’