cholesterol is synthesized by all animal cells and is an essential structural component of animal cell's membrane cholesterol is the most common steroid and mainly synthesized in the liver cholesterol also serves as a processor for several important biological compounds including all except insulin ,vitamin D, bile salts , testosterone.

Aug 11, 2017 — Vitamin D3 is produced in the skin from 7-dehydrocholesterol by UV irradiation, 1,25(OH)2D reduces 1,25(OH)2D levels in cells primarily by Animals null for calbindin 9k (the major calbindin in mammalian abnormal vitamin D and/or calcium metabolism in some but not all of these patients (24-26). Cholesterol, a waxy substance that is present in blood plasma and in all animal tissues. it is a primary component of the membrane that surrounds each cell, and it is synthesizes bile acids, steroid hormones, and vitamin D. Cholesterol are essential energy sources and structural components of all life