In this video, Dr. K K Aggarwal, Padma Shri Awardee, Editor-in-chief IJCP Publications, will discuss about to treat or supplement vitamin D deficiency patients in this video. There are different protocols for the treatment. One of the protocols is that if the levels are less than 10 ng/dl then give 60 K IU of Vitamin D3 once in a week for 8 weeks followed by a maintenance therapy. Dr. Aggarwal will also explain how much doses is required in obese and mal-absorption syndrome patients. The parenteral Vitamin D should not be the first line of treatment.