What's the deal with Vitamin D?

We've all heard about Vitamin D, it's all the rage. We get it when we are in the sun but in the winter everyone is saying we are depleted of it due to lack of sunshine. I recently listened to an interview about a program called The Marshal Protocol. I won't go in to great detail about that but the topic surrounds some of latest research about Vitamin D. It made me question my assumption that it is something I should be taking. There's always an opinion on every subject so I'll leave you a link to the website where you can hear the interview for yourself.

First of all, apparently it's not technically a vitamin but a steroid. It's marketed as a vitamin, I suppose because steroid D wouldn't sound to appealing. The common knowledge is that "vitamin" D is great for your immune system which is why I am confused. According to some of the latest research, Vitamin D actually suppresses the immune system.

When you are sick you are feeling the toxic die off effects of your immune system at war with all the yucky bacteria in your system. If your immune system is suppressed, there's no conflict hence you feel great but then where does that leave your body in the long term?

How could this be when vitamin D has been glorified throughout the medical community at large? Even Dr. Oz said that it is at the top of the list of things that Americans are deficient in. So I guess the answer to this is left up to you. I like to go with concrete evidence. Where is the research?
What are the pros and cons of taking this supplement? Can I use sun lamps as a replacement for D3 if I have seasonal effective disorder? These are a few of the questions we might ask.

Whether you choose to take Vitamin D is Obviously up to you but I posted this because I think it is important to know all the facts about the supplements you are taking. Lately I've been realizing that just because something is popular in the vitamin world, doesn't mean it is a good thing to be ingesting.

The link I provided for information about the Marshal Protocol is an interview that covers a method mainly for those with autoimmune issues. This would be a personal choice as it involves pharmaceuticals in small doses. I think we can all agree that getting vitamin D from the sun is a good thing, I know I feel graet when I'm in the sun more often.

Links:
http://www.oneradionetwork.com/health_-_podcasts/open_friday_forums/the_pros_and_cons_of_taking_vitamin_d_-_the_marshal_protocol_-_01.16.10_201001161490/

http://bacteriality.com/

http://www.naturalnews.com/003069.html

http://www.marshallprotocol.com/forum2/4213.html