DECIDING whether to avoid direct sunshine just became more
complicated. Keeping out of the sun helps avoid skin cancer, but
sunshine also allows your skin to manufacture vitamin D, which
plays a key role in preventing colorectal cancer. In a review of
studies examining links between vitamin D and colorectal cancer,
Cedric Garland and his colleagues at the University of
California, San Diego, conclude that taking 1000 units, or 25
micrograms, of the vitamin daily - equivalent to five times US
guidelines for young adults - halves the risk of colorectal
cancer. Vitamin D is thought to prevent colorectal cancer by
helping the lining cells of the gut stick together properly,
preventing the formation of pre-cancerous polyps. "What's clear
is that 1000 units is the minimum to produce an effect," says
Garland. The team estimates that if all US adults consumed 1000
units of vitamin D per day, it could ... To continue reading
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