Which statement about vitamin D is accurate?

Show Answers

Its absorption depends on the presence of bile salts.Its production is controlled by the enzyme 15-hydroxylase.Lack of it in adults causes rickets.Together with parathyroid hormone, it promotes calcium release from bones.

Explanation

Option D is correct because vitamin D, in combination with parathyroid hormone (PTH), enhances the mobilization of calcium from bone into the bloodstream. Option A is incorrect since absorption requires bile salts, not pigments. Option B is false because synthesis regulation involves 1-alpha-hydroxylase, not 15-hydroxylase. Option C is wrong because vitamin D deficiency causes rickets primarily in children, while in adults it leads to osteomalacia.