Canada's Cancer Society on Thursday urged people to increase vitamin D intake, citing growing evidence of the supplement reducing cancer risks.
The society recommended that adults living in Canada should consider taking 1,000 international units (IU) of vitamin D supplements a day during the fall and winter.
Adults at higher risk of having vitamin D deficiency, including older people, those with darker skin, not going outside often or wearing clothing that covers most skin, should consider taking the 1,000 IU supplement year round, the society said in a statement.
"We're recommending 1,000 IUs daily because the current evidence suggests this amount will help reduce cancer risk with the least potential for harm," said Heather Logan, the society's director of cancer control policy.
A study published Thursday in the "American Journal of Clinical Nutrition" showed a 60 to 77 percent drop in cancer rates among postmenopausal women who took vitamin D combined with calcium, compared with a placebo.