BIOMOLECULES AND ENZYMES

Detailed explanation-1: -A unique aspect of vitamin D as a nutrient is that it can be synthesized by the human body through the action of sunlight. These dual sources of vitamin D make it challenging to develop dietary reference intake values. Vitamin D, also known as calciferol, comprises a group of fat-soluble seco-sterols.

Detailed explanation-2: -Vitamin D is a secosteriod hormone essential for calcium absorption and bone mineralization which is positively associated with bone mineral density [BMD].

Detailed explanation-3: -Vitamin D has indirect action on bones by regulating the calcium and phosphate metabolism of the body. The main organs involved in this regulation are the intestine and kidneys.

Detailed explanation-4: -The endogenous serum metabolite of vitamin D (calcitriol, 1, 25(OH)2 D3 ) is considered a true steroid hormone (D hormone), and like glucocorticoids (GCs) and gonadal hormones, may exert several immunomodulatory activities.