Do vitamins really work?

With around one in 10 people taking supplements, the vitamin industry is booming as never before. And around a quarter take expensive "high-dose" vitamins that aim to maximise the body's health.

But with some optimum-nutrition brands costing up to 10 times more than basic multivitamins, are they really worth the money?

To find out we asked two women to take two leading vitamin brands for a month, one the most expensive, the other the most inexpensive. Before and after we tested the women's antioxidant levels - which provides protection for the body against many diseases and premature ageing - to measure the effectiveness of the two vitamin brands.

LOW-DOSE FORMULA

Antioxidant levels before: 59 Antioxidant levels after: 69 Increase: 10 points

WHAT'S IN IT? Sanatogen Gold multivitamins (£4.39 for 30): These tablets contain the recommended daily allowances for a wide range of vitamins and minerals. As the RDAs correspond to the amount your body needs to prevent deficiency - not to prevent disease - these supplements make no health claims. They contain 60mg of vitamin C, 10mg of vitamin E and 800iu of vitamin A. Minerals include 173mg of calcium and 15mg of zinc.

FEEL ANY DIFFERENT? Janette Vince, 42, who has her own web business, thanksdarling.com, organising unusual gifts, took Sanatogen Gold multivitamins for a month.

She says: "Running my business is stressful, and I don't always eat well. Although I didn't feel any different, I'm convinced the vitamins did me good, particularly since I've recently started on a wheat, sugar and dairy exclusion diet because of my rheumatoid arthritis."

ANALYSIS: This formula appeared to be highly effective. "Janette's antioxidant measure went up by 10 points, which is significant considering that the dose of vitamins in these supplements is relatively low," says Patrick Holford, leading nutritionist and founder of the Institute of Optimum Nutrition. "It shows they must have been well-absorbed and that even inexpensive vitamins can benefit health.

Janette's final antioxidant levels were 69, which is moderate. She should aim to be in the 80s to help combat the inflammation of her arthritis."

However, Dr Anne Nugent of the British Nutrition Foundation says: "This shows that standard multivitamins have such a significant effect, that when combined with a healthy diet, most people shouldn't need more than that."

VERDICT: A very significant impact on Janette's nutrient status.

HIGH-DOSE FORMULA

Antioxidant levels before: 64 Antioxidant levels after: 86 Increase: 22 points

WHAT'S IN IT? The Higher Nature 100% Health Pack (£47, tel: 01435 884668) contains Immunec, a combination of vitamin C, zinc, bilberry, elderberry and cat's claw; Advanced Optimum Nutrition Formula, a multivitaminandmineral supplement; and two capsule packs of Essential Omegas.

Four capsules are to be taken twice a day and contain 2,000mg of vitamin C, 200mg of vitamin E, 1,500iu vitamin A, 20mg of zinc and B-vitamins. The supplements also contain flavonoids, a wide range of minerals including 680mg of calcium.

While the pack makes no direct health claims, the labels suggest the supplements can boost immunity, improve IQ and reduce colds.

FEEL ANY DIFFERENT? Leone Ashby, 28, a PR executive for Nivea, took this formula for a month. She says: "Work has been very stressful. But while taking the vitamins I didn't feel as tired as usual. And while everyone else in the office went down with flu, I was fine. My skin also seemed to glow."

ANALYSIS: Compared with the lowdose formula, this pack contains about 30 times the amount of vitamin C, 20 times the vitamin E, twice the vitamin A, and four times the amount of calcium. Yet they only raised Leone's antioxidant levels by 12 points more than the low-dose brand.

But Patrick Holford says: "Leone's antioxidant levels reached 86 - a high level. If sustained, her antioxidant levels would indicate protection against heart disease, cancer and many other processes associated with ageing."

But is the 12-point increase really worth paying 10 times the cost for?

Dr Anne Nugent doesn't think so. "With some vitamins, such as vitamin C, you only absorb what you need," she says. "Most people eating a healthy balanced diet shouldn't need supplements. But if you're busy and not eating properly we would recommend a standard multivitamin and-mineral supplement."

VERDICT: The formula raised Leone's antioxidant levels by 25 per cent. But how significant the benefit is for the dose and cost remains open to debate.