Tanning while pregnant

Annya26

So I feel like a bad person for even asking this, because I know you aren't supposed to go into tanning beds when you are pregnant but I'm going to ask anyway.

Why are we not allowing? Is it the heat? The UV rays? Something I'm not thinking of? We don't have to avoid sun in general, so what is it that says we can't go in a tanning bed?

The reason I am asking is because I have been known to have pretty nasty SAD (seasonal affective disorder) during the winter months and used to go tanning for a whopping 8 minutes every two weeks to get some vitamin d and feel better. Didn't really even give me a tan, just helped me to feel better. So I'm wondering if this is something that is safe to do so I don't have to deal with the low lows on top of the hormones, or if I'm just a crappy person for even considering it?