24.25- Dihydroxyvitamin half-life

L The answer is e. (Kalzang, pp 744, 748J Vitamin is hydroxylated to 2.5-0ITDj (calcifediol). Calcifediol is then hydroxylated in the kidney to the most active form of vitamin D, which is 1,25-dihydroxyvitamin D (cal-citriol). Calcitriol has a rapid onset of action and a short half-life. The administration of calcitriol causes the elevation of serum Ca levels by enhancing the intestinal absorption of Ca. Calcitriol is indicated in vitamin D deficiency,... 

I9)-trien-1.3.2S-triol. 1,2S-dihydroxycholecalciferol. l.2S-dihydroxyvitamin D.r, occurs as colorless crystals that are insoluble in water. Bccau.se calcitriol does not require activation, increased calcium absorption is seen within 2 hours of administration. Its half-life is 3 to 8 hours, and its duration of action is I to 2 days. 

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