Hi, I am a 54 y/o women with Vit D value of 20. (I was tested years ago and it was 25.) I have been experiencing fatigue for years and attributed it to Wellbutrin and Celexa. After reading about Vit D, I am wondering if I will feel better with increasing my levels. I am in week 1 of 50,000 IU and will be retested at week 13. Also wondering how long it may take to feel the positive effects of Vit D?