16 November 2001

Drive to increase vitamin E levels

INCREASING vitamin E in milk could extend its shelf life and benefit human health, but it is proving difficult to achieve.

Potential benefits prompted research into developing strategies for increasing vitamin E in milk, says ADAS researcher Angela Moss.

"But only small increases in milk vitamin E concentration have been achieved when supplementing the vitamin in dairy rations."

This is due to a low efficiency of transfer with less than 0.5% of dietary vitamin E being secreted in milk. The small response could be because vitamin E is being destroyed in the rumen, she says.

But one study at ADAS found no benefit in feeding rumen protected sources of the vitamin on its content in milk. This suggests other factors are limiting vitamin E secretion in milk.

A similar study at Harper Adams University College, Shropshire, found limited responses in blood levels of lambs when fed vitamin E supplements, says the colleges Liam Sinclair. "This suggests other factors, such as poor intestinal absorption, were limiting its uptake by the animal."