1alpha,24S-Dihydroxyvitamin D2
LR-103 is a naturally occurring D-hormone that is produced by the kidneys from vitamin D. LR-103 is one of the D-hormones produced from Hectorol. It is developed for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease (CKD). Studies have shown LR-103 has the same potency as calcitriol, but much lower toxicity.