I am 20 years old and was just told i have an extremely dangerously low level of Vitamin D, and they have prescribed me 50,000 units per week for the next 3 months. This explains why I was so tired I could fall asleep standing up, and had such a hard time with energy. I could sleep 18 hours and still be exhausted to barely be out of bed! I have daily headaches, horrid back pains for years, and pains that radiate through my bones all the time. They did not do a bone scan so maybe that should be my next step. I also live in upstate new york and am not allowed to go in the sun for risk of skin cancer because i am so fare skinned. All of these problems I have complained for years and finally i got the right person to look into it and I start my medication today, hoping to feel more my age soon! Been years since i was able to be a teen, and i don’t want to be old yet!