The main symptoms of vitamin D overdose which are those of hypercalcemia including anorexia , nausea, and vomiting. These may be followed by polyuria , polydipsia , weakness, insomnia, nervousness, pruritus and ultimately renal failure . Furthermore, proteinuria , urinary casts , azotemia , and metastatic calcification (especially in the kidneys) may develop.  Other symptoms of vitamin D toxicity include mental retardation in young children, abnormal bone growth and formation, diarrhea, irritability, weight loss, and severe depression.  
Vitamin d is widely used around the world to treat this skin problem. Vitamin d plays a role in skin cell metabolism and growth. Therefore, it has shown some effectiveness in treating itching and flaking which are common symptoms of this skin problem. Studies have indicated that over the counter type vitamin d creams are not very effective at treating psoriasis because they do not contain the active vitamin d derivative. The active vitamin d form is only available in prescription creams or supplements. Several weeks of treatment are normally required to relieve the psoriasis symptoms. A big advantage is that vitamin d creams have few side effects, unlike steroid containing creams.
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