Was a vitamin d deficiency causing random aches? after supplementing vitamin d3 at 2000iu for a few weeks, i had a blood test which showed 34.6 ng/ml.

Not the reason: Your levels are normal since supplementing. Every week in medicine a new medical disorder is linked to Vitamin D deficiency. At the same time studies are published just as frequently showing that Vitamin D supplementation does not reverse the condition or symptoms. It is VERY unlikely deficiency is causing your symptoms. Most people with Vitamin D deficiency don't have any symptoms.

Yes: Severe vitamin D deficiency causes rickets in children, and osteomalacia in the elderly. Vitamin D is a sterol synthecised from cholesterol, like other hormones, and is active in many different metabolic pathways; people with deficiency have significantly higher rates of depression, myalgia, colon and breast cancer, and immune disorders. It is stored in our fatty tissue.