Calcium Hydroxy Apatite is a coral constituent.
Besides the oestrogen level, I would suggest that you check your parathyroid function before supplementing with calcium as there is another side of the coin related to excessive calcium level in blood.
Better to discuss this with your doctor.
With best wishes,
Alla Cranham, MSc ABMT,
Registered Homotoxicologist
Mercury House
Northgate
Nottingham
NG7 7FN
Tel +44(0) 845 450 7316
Mob +44(0) 77361 47458
Fax +44(0) 115 9163109
http://www.in-vivo-health.co.uk