Vitamins may hold up breast cancer

The supplements are thought to help cells to repair damaged DNA using a process that involves more than 200 proteins.

Professor Jaime Matta, from the Ponce School of Medicine in Puerto Rico, said: "It is not an immediate effect. You don't take a vitamin today and your breast cancer risk is reduced tomorrow. However, we did see a long-term effect in terms of breast cancer reduction.

"This process involves at least five separate pathways and is critical for maintaining genomic stability. When the DNA is not repaired, it leads to mutation that leads to cancer."

Prof Matta's team compared 268 breast cancer patients and 457 healthy women.

Taking different kinds of vitamin supplements appeared to reduce the risk of breast cancer by about 30 per cent and calcium supplements by 40 per cent.

"We're not talking about mega doses of these vitamins and calcium supplements, so this is definitely one way to reduce risk," said Prof Matta.

The findings were presented yesterday at the American Association for Cancer Research annual meeting, which was being held in Washington DC in the United States.