Microcrystalline Hydroxyapatite

Microcrystalline hydroxyapatite compound in prevention of bone loss in corticosteroid-treated patients with chronic active hepatitis.
Stellon A, Davies A, Webb A, Williams R.
Postgrad Med J. 1985 Sep;61(719):791-6

 To determine whether microcrystalline hydroxyapatite compound (MCHC) could reduce bone loss or its consequences in patients with chronic active hepatitis (CAH) on corticosteroid therapy, a controlled trial was conducted in 36 such patients over a period of 2 years. Both skeletal symptoms (back pain) and fractures were uncommon during the trial period but both showed non-significant differences in favour of the MCHC group and biochemical investigations were suggestive of a reduction in parathyroid over-activity. Continued reduction in bone mineral content of the radius (photon absorptiometry) was halted in those receiving MCHC and iliac crest bone biopsy showed a non-significant increase in trabecular bone volume. The fall in iliac crest cortical plate thickness was significantly less (P less than 0.025) in the MCHC group and the results overall were consistent with a beneficial effect from MCHC in corticosteroid-induced osteoporosis. PMID: 2997764

  Raloxifene plus ossein-hydroxyapatite compound versus raloxifene plus calcium carbonate to control bone loss in postmenopausal women: a randomized trial.
Pelayo I, Haya J, De la Cruz JJ, Seco C, Bugella JI, Diaz JL, Bajo JM, Repolles M.
Menopause. 2008 Nov-Dec;15(6):1132-8.

 To compare the efficacy and safety of adding ossein-hydroxyapatite compound (OHC) or calcium carbonate (CC) to raloxifene (RLX) therapy for controlling bone loss in postmenopausal women. Ninety postmenopausal women were assigned to treatment with RLX plus OHC (group 1, 48 women) or RLX plus CC (group 2, 42 women) for up to 3 years in an open-label, comparative study. Ultrasound measurement of amplitude-dependent speed of sound (ADSoS) was used to evaluate mean changes in bone mineral density. The primary endpoint was mean change of ADSoS from baseline. An intention to treat and per protocol analysis were carried out. Adverse effects were also recorded. Over the study period, the mean ADSoS diminished in both groups even though the rate of reduction was higher in the RLX plus CC group, with a mean change in ADSoS score of -18.72 m/s from baseline to year 3 in the RLX plus OHC group and -63.64 m/s in the RLX+CC group (P = 0.006). Similar results were seen on T and Z scores. Adverse effects were infrequent and the number and type were similar between groups. RLX plus OHC appears to be more effective in controlling bone loss than RLX plus CC for the control of bone loss in postmenopausal women. PMID: 18791486

  Preventing postmenopausal bone loss with ossein-hydroxyapatite compounds. Results of a two-year, prospective trial.
Castelo-Branco C, Pons F, Vicente JJ, Sanjuán A, Vanrell JA.
J Reprod Med. 1999 Jul;44(7):601-5.

 To evaluate, in postmenopausal women who refuse hormone replacement therapy (HRT), whether continuous administration of an osseinhydroxyapatite compound (OHC) reduces bone loss and protects from osteoporosis. Sixty postmenopausal women were included in an open study and were allocated to three groups. The first group (n = 19) received treatment consisting in 3.32 g/d of OHC per day, the second group (n = 21) received 2.5 g of calcium carbonate per day, and the third group (n = 20) was a treatment-free control group. Bone mineral density (BMD), assessed by dual x-ray absorptiometry, was measured prior to and at 12 and 24 months of treatment. Subjects on OHC therapy did not show significant changes related to baseline on bone mass across the study, whereas a significant decrease was detected in the calcium carbonate group during the second year (-3.7%, P < .05) and in the control group at the first and second BMD measurement (-3.5%, P < .05; -5.6%, P < .01). Continuous administration of OHC prevents bone loss in postmenopausal women, suggesting that this drug may be useful in the management of postmenopausal bone loss. PMID: 10442322

  Calcium metabolism in bone disease: effects of treatment with microcrystalline calcium hydroxyapatite compound and dihydrotachysterol.
Dent CE, Davies IJ.
J R Soc Med. 1980 Nov;73(11):780-5.

 Microcrystalline calcium hydroxyapatite compound (MCHC) was given orally together with small doses of dihydrotachysterol (DHT) to a number of patients with osteogenesis imperfecta (OI). Serial calcium and phosphate balances in three patients representing wide variations in severity of OI are presented over periods from eight months to two years. The combination of MCHC and DHT resulted in an immediate positive calcium balance which was maintained throughout the period of assessment in 2 cases. However, no radiological improvement could be demonstrated. Substituting calcium gluconate for MCHC resulted in a reduction of positive balance. No adverse effects were noted. The reasons why MCHC with DHT should result in increased calcium retention are discussed. This combination of MCHC and DHT could be of benefit in many common situations of bone demineralization, such as osteoporosis. PMID: 6264079