Vitamin D and cancer link needs to be "clarified" says Cancer Research UK
Cancer Research UK has played down reports of a protective role for vitamin D in breast cancer development.
A study published in the Journal of Clinical Pathology this week led to suggestions that higher levels of vitamin D in the blood might slow breast cancer growth.
The study found that vitamin D levels in the blood of women with breast cancer were higher among women in an early stage of the disease than when the disease was more advanced.
The research did not provide any further findings into what the role of vitamin D in breast cancer might be, however.
"This relatively small study shows that blood vitamin D levels are higher in patients with early stage breast cancer than in those with more advanced breast cancer," said Sara Hiom, Cancer Research UK's deputy director of cancer information.
"It does not tell us why this is nor does it clarify whether the advanced disease is a consequence of the low vitamin D levels or vice versa.
"We need well designed large-scale studies to establish the precise role of vitamin D in the progression of human cancer."
The study was conducted by Imperial College in London.