Drinking organic milk has more health benefits than drinking non-organic, a study has suggested.
Milk from cows reared differently was compared
The research was presented to the Soil Association's annual conference in Newcastle.
It showed organic milk has higher levels of vitamin E, omega 3 essential fatty acids and antioxidants, which help beat infections.
But nutritionists said people who drank non-organic milk would be getting these nutrients from other sources.
The research was carried out by a team from the Danish Institute of Agricultural Research, which is part of the University of Newcastle's Quality Low Input Food (QLIF) Congress.
Milk was tested from cows who were farmed organically and conventionally.
The study found cows farmed organically produced milk which was, on average, 50% higher in Vitamin E than conventionally produced milk.
Organic milk was also 75% higher in beta carotene, which is converted into Vitamin A in the body.
It was also two to three times higher in the antioxidants lutein and zeaxanthine.
Antioxidants are the naturally occurring substances in plants that protect the body from free radicals - 'bad' chemicals in the blood.
Free radicals alter cholesterol in a process known as oxidation, which is thought to speed up the hardening of the arteries.
Higher levels of omega 3 essential fatty acids, which are believed to help provide protection from coronary heart disease, were also found in organic milk.
The study concluded that drinking a pint of organic milk a day would provide 17.5% of the required daily intake of Vitamin E for women, and 14% of that for men.
The researchers suggest it also provides as much beta carotene as a portion of vegetables, such as brussel sprouts.
They say organically-reared cows benefit from having more room to graze than conventionally-reared cows.
Professor Carlo Leifert, QLIF project leader, told the conference: "Clearly, to convince the scientific community as a whole we need further evidence and the EU Quality Low Input Food project is very much focused on confirming and explaining the differences in milk composition shown in these studies."
Patrick Holden, director of the Soil Association, added: "This new research adds to a growing body of evidence proving the health benefits of organic food.
"A number of schools are now serving organic milk, and there is now a strong case for the government to ensure that such initiatives are extended across the country."
Jill Eisberg, chief executive of The Dairy Council called the research "an interesting new development for the dairy industry".
But she added: "For any cow, if the feed is modified this will come through in the milk produced - this is not unique to milk produced by organically farmed cows."
Ms Eisberg said the findings presented at the Soil Association's conference were interim results and had not been published or peer-reviewed.
Dr Anne Nugent, of the British Nutrition Foundation, said: "It is important to note that there were no differences highlighted between the two milks for some of the major nutrients that milk provides, such as calcium and vitamin B12.
"It is important to encourage people to continue to consume milk and milk products - whether they choose organic or regular milk will be a matter of personal preference and choice."
She added: "The main dietary sources of vitamin E are fat spreads; for beta carotene it is fruit and vegetables, and for omega 3 fats cereal and cereal products, meat and meat products and also fish.
"So even if regular milk is slightly lower in these nutrients than organic milk, chances are you will be already be meeting your dietary needs for these nutrients by consuming other foods."