Just had my first series of blood work done by my GI doctor. She tested to see what my Alpha-1-Antitrypsin that came out normal. She tested my Magnesium levels, those were prefect. My vitamin D levels were very low at 16.7 out of a range of 30-100 ng/mL. I stated taking a 400 UI of vitamin D3 two weeks ago. Are these vitamin D levels something that takes...