@geranium1 This is what I found--thanks for the question, as I learned something new!

Health Benefits
Microcrystalline Hydroxyapatite (MCH)
Supports bone density and strength.
Provides a more balanced release of calcium, reducing cardiovascular risks associated with spikes in serum calcium.
Hydroxyapatite (HA)
Used in dental applications and bone grafts.
Helps in bone regeneration and repair.
Both forms are beneficial for bone health, but MCH is often preferred for dietary supplementation due to its additional nutrients and lower impact on serum calcium levels.