Last year I had a blood test thru Athlete Blood Test (ABT) company that showed that I was deficient in Vitamin D. While I was not surprised to some degree, as it was during the winter and that my German/Italian blonde hair and blue eyes, never liked to be in the sun because I always got burned so easily with this type of genetics. With this Blood test, I was able to truly understand the implications of having low or deficient levels of Vitamin D in the body. Some symptoms low levels of Vitamin D include fatigue/tiredness, back pain, depression, bone/hair loss, muscle pain and weak immunity and frequent sickness. Read more