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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
The major storage and circulatory form of vitamin D is:-
assistant
The correct answer is  Cholecalciferol is first hydroxylated at 25th position to 25-hydroxycholecalciferol (25-OH o3) bv a specific hydroxylase present in  liver. 25-OH D3 is the major storage and circulatory form of vitamin D.
Reference: Satyanarayana- Biochemistry, 3rd edition, pg-125