A lack of melanin can cause deficiency of this secosteroid, which is available as a supplement due to its role in reducing the risk of osteoperosis.
This compound is linked to the synthesis of cathelicidin, a peptide that attacks tuberculosis, and its medical uses include topical application for psoriasis treatment. This compound becomes biologically active after a conversion in the liver that adds 25 hydroxyl groups, and then by 1-alpha- hydroxylase in the liver, to produce another compound used to determine levels of this chemical in the body. Its most common form is known as (*) cholecalciferol, likely from the fact that it is combined with cholesterol by the parathyroid glands in response to low calcium levels. A lack of melanin can cause deficiency of this secosteroid, which is available as a supplement due to its role in reducing the risk of osteoperosis. For 10 points, name this fat-soluble vitamin whose production can be stimulated by sunlight and whose deficiency in children leads to rickets.
This compound is linked to the synthesis of cathelicidin, a peptide that attacks tuberculosis, and its medical uses include topical application for psoriasis treatment.
vitamin {D} [most of the clues refer to {D}{3}, so accept it]