Study in Healthy Volunteers, to Evaluate the Safety, Efficacy and Dose Responses of SB-751689 (Ronacaleret)

Inclusion Criteria: * A male or female between 18 and 65 years of age (inclusive). * Healthy as determined by a physician, based on a medical evaluation and with an estimated Glomerular Filtration Rate (GFR) of \>=60 mL/min /1.73 m\^2 using the four variable Modification of Diet in Renal Disease (MDRD) equation. * Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase and bilirubin \<=1.5 x upper limit of normal (ULN) (isolated bilirubin \>1.5 x ULN is acceptable if bilirubin is fractionated and direct bilirubin \<35%). * Female of non-child bearing potential, or female subjects and male subjects with female partners of child-bearing potential willing to use protocol-specified methods of contraception to prevent pregnancy during the study. * Body weight of 55 kg or more and body mass index (BMI) of 20.0 to 35.0 kg/m\^2 (inclusive). * Capable of giving written informed consent. Exclusion Criteria: * A positive pre-study drug/alcohol screen. * A positive test for HIV, B surface antigen or positive Hepatitis C antibody result within 3 months of screening. * History of or therapy for osteoporosis * Subject has had treatment for any condition relating to the thyroid/parathyroid gland which in the opinion of the investigator may influence the subjects production of PTH * Subjects with any contraindications or know allergies to receiving plerixafor * Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of asymptomatic gallstones). * Subjects taking calcium and/or vitamin D supplements, during or within 2 weeks of study initiation * Subjects taking any concomitant medications * Specific laboratory abnormalities at screening like Serum calcium (total or albumin-adjusted) outside the central laboratory reference range, PTH outside the normal range, Creatine phosphokinase (CPK) outside the normal range * Subjects with abnormal Vitamin D (Vitamin D, 25-Hydroxy) levels may be enroled if repeat lab results, obtained within 14 days of initial screening assessments, are within the normal range * History of regular alcohol consumption within 6 months of the study defined as an average weekly intake of \>14 drinks for males or \>7 drinks for females. * Lactating or pregnant females as determined by positive serum human chorionic gonadotropin (hCG) test at screening or prior to dosing. * The subject has participated in a clinical trial within 30 days or 5 half-lives of the IP prior to the first dosing day in the current study. * Unable to refrain from consumption of red wine, Seville oranges, grapefruit or grapefruit juice from 7 days prior to the first dose. * Where participation in the study would result in donation of blood or blood products in excess of 500 mL within a 56 day period.