He didn’t specify though. Cooked and raw spinach have very different nutritional properties, so it makes sense to eat both.

The minerals stay the same. It's just the vitamins that are decreased. But, spinach has such a vast amount of vitamin A,C,K to start with, it hardly matters.

The acid brought out in cooking doesn’t just decrease the nutrients, it allows some nutrients to be absorbed easier, so it’s a bit more complex.