I am having severe Deficiency of Vitamin D that is 6.49 ng/ml. Due to that I am having severe back pain also and feels light pain in other body parts and bones. As I studied lil bit regarding vitamin D severe Deficiency causes can be less or negligible exposure to sunlight may be the reason. So my concern is that is this could be the only reason or something else. I am pure vegetarian not talking even Eggs. So apart from sunlight how can we increase vitamin D. Also another question is that due this severe Deficiency of Vitamin D my bones might become brittle so can I do some exercise with physiotherapist to subsidize my back pain or doing exercise in this situation will make my condition worst or it will be helpful.