Racquetball + Weight

I went to my racquetball class for the first time in two-and-a-half weeks. (I hadn't been feeling well, so I didn't go.) I told my teacher that I had been sick and that my immune system sucks, and he told me I should look into taking Vitamin D3 supplements. Have any of you taken them?

Also, I weighed myself at the gym for the first time in over a month. 140.5 pounds. Pretty normal. Need to get back on track if I want to lose that 20.5 pounds to hit my first goal weight.