What type of nutrient deficiency is associated with impaired collagen synthesis leading to easy bruising?

The association of impaired collagen synthesis and easy bruising is primarily linked to vitamin C deficiency. Vitamin C, also known as ascorbic acid, is essential for the hydroxylation of proline and lysine residues in collagen synthesis. This hydroxylation is crucial for the stability and strength of collagen fibers, which are integral components of connective tissues, skin, and blood vessels. When there is a deficiency of vitamin C, the synthesis of collagen is disrupted, leading to weakened blood vessels that are more prone to rupture, causing easy bruising.

The other nutrient deficiencies listed do not have the same direct impact on collagen formation. Vitamin A is primarily involved in vision and cellular differentiation, vitamin D is crucial for calcium metabolism and bone health, and vitamin K plays a significant role in blood coagulation rather than collagen synthesis. Thus, while deficiencies in these vitamins can result in various health issues, vitamin C deficiency is specifically linked to the impairment of collagen synthesis and the resultant bruising.