Does freezing food reduce its nutritional value?

im not sure the act of freezing does, but your method of reheating could potentially reduce its nutritional value. microwaves are especially notorious for this.

Freezing does break down some of the nutritional value, so does cooking. If you want to eat food at its optimal nutritional value, eat it raw.

I thought that veggies that were flash frozen retained more of its nutritional value than veggies that are canned since the canning process uses high heats that would break down the vitamins and nutrients.

While I agree that fresh is always best, I think frozen is better than no veggies at all.

most all frozen veggies are par boiled first