vitamin deficiency!

I was deficient in D as well, my pcp also said you pretty much need to take a supplement, and try to get 15 min of sunlight a day. Apparently a lot of sunlight is absorbed through the eyes, so don't wear sunglasses for that 15 mins.

Depending how deficient you are, you may need injections to get you up to levels, then take supplements. I had 2 injections. My dr said it was very hard to bring up only using oral meds

If your body is vit D deficient, then you're not metabolizing calcium either. You need vit D for your body to use calcium, however you don't need calcium for your body to use vit D. Your doc is the best place to get the suggested dosages. I also had low vit D pre-op and brought it up to acceptable levels  before surgery, even though I discontinued all vitamins, minerals and supplements 2 weeks prior to surgery. Now I'm just as fastidious about taking my vitamins and supplements. My problem is iron. Makes me terribly nauseated. A pharmacist gave me a tip, freeze the iron pills, the breakdown process occurs in the small intestines instead of the stomach (this only works for VSG patients and not for RNY) and lowers the incidence of nausea.

Vitamin D deficiency is pretty common, what with so much indoor activity these days (even in the summer) and use of sunscreen when we're outdoors.  I was told I was deficient in D long before my WLS.  I take 3000 IUs daily, chewable.

A huge bit of the population is deficient on D3.  Don't skimp on the supplements, though, for it affects immunity, mood, and calcium absorption. 

It's nice to want to get your D naturally, from food. The problem is, D is not present in many foods naturally. Most things that are high in D, like milk, have D added at the factory. To me, there is no difference between a factory adding vitamins to my food, or me just taking the D myself.

Make sure you are taking D3 instead of D2. D2 is pretty useless.