Higher levels of Vitamin D among women may reduce their risk of developing breast cancer post menopause, claimed a new study.
The study found that women with blood levels of serum 25-hydroxyvitamin D (OH) - the main form of vitamin D in blood - above 60 ng/ml (nanograms per millilitre) had one-fifth the risk of breast cancer compared to those with less than 20 ng/ml.
Thus, researchers from the University of California-San Diego determined that the minimum healthy level of 25(OH) in blood plasma should be 60 ng/ml, instead of the earlier recommended higher than the 20 ng/ml.
"Increasing Vitamin D blood levels substantially above 20 ng/ml appears to be important for the prevention of breast cancer," said lead author Sharon McDonnell from GrassrootsHealth, a non-profit public health research organisation.
The study, published in the journal PLOS ONE, analysed data from two randomised clinical trials with 3,325 combined women and a prospective study involving 1,713 women with average age of 63.
Participants were free of cancer at enrolment and were followed for a mean period of four years. Vitamin D levels in blood were measured during study visits.
"This study was limited to postmenopausal breast cancer. Further research is needed on whether high 25(OH)D levels might prevent pre-menopausal breast cancer," said Cedric F Garland from UC-San Diego.