Organic milk contains the same nutrients as conventional milk, including vitamin D, potassium and calcium, although studies have suggested organic milk has higher levels of antioxidants, vitamins and fatty acids. To qualify as organic, milk must come from cows that have not been treated with antibiotics or synthetic hormones, eat organic feed without animal by-products and have pasture access during the grazing season. As of 2015, researchers have not reached a consensus on whether organic milk provides health benefits.
Organic milk has higher levels of some nutrients, such as omega-3 fatty acids, that scientists believe reduce the risk of cancer, cardiovascular disease and other illnesses. However, organic milk does not possess these nutrients in large enough quantities to suggest a noticeable health benefit.
Research suggests the higher nutrient levels found in organic milk are primarily due to cows' access to grazing pastures and not other factors, suggesting milk from pasture-fed non-organic cattle offers benefits similar to organic milk.
Organic milk is typically more expensive than conventional milk. One reason for the price difference is a limited supply of organic dairy farms. It takes farms three years to achieve organic certification, and they may face additional challenge once certified, such as the shortage of organic feed that disrupted supply chains in 2011.