Category: mineral
Aliases: Ca²⁺, Calcium citrate, Calcium carbonate, Hydroxyapatite
Second messenger released from smooth/skeletal ER and mitochondria via ryanodine and IP3 receptors; binds calmodulin to activate downstream kinases/phosphatases and contractile machinery. Active intestinal absorption via TRPV6 is calcitriol-dependent; paracellular absorption dominates at high intakes. Hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) is the bone mineral matrix; bone is the dominant body pool.
PO: 5h