Do you loose nutrients when you freeze organic milk?

You may consider culturing some of the milk you purchase as a preservation technique rather than freezing it

It turns out that the vitamin C in milk may be as cold-sensitive as it is heat-sensitive.

researchers found that riboflavin (vitamin B2) showed little loss in either freezing or pasteurization

However, thiamine (B1) is more sensitive to heat than to freezing

The numbers of beneficial bacteria do decline when raw milk is frozen however the loss depends on the amount of time in the freezer.

One study found that antioxidants are at their peak in human milk in its first two days. There is loss with both time and with freezing

source: rawmilkwhitepapers.com

Although there is a change in the vitamin and mineral status due to freezing, the enzymes and bacteria in the raw milk simply fall into a dormant state while frozen, and become active again after thawing.

source: Ehow.com

The actual bacteria count declined from 500 million to about 100 million in the first week. The defrosted milk will still have a good bit of bacteria, just not nearly as much as the fresh milk. Freezing certainly is far easier on bacteria than is pasteurization.