Short answer: Calcium (as Calcium Carbonate, 18mg) plays a documented role in nerve signaling, helping regulate the electrical signals neurons use to communicate.
Why "documented role" is a specific, checkable claim
Calcium's involvement in neural electrical signaling is a well-established area of biology, distinct from the formula's more novel nitric oxide framing.
Why this dose is modest compared to typical daily calcium needs
18mg · 1.5% DV — a small fraction of typical daily calcium intake, reflecting this ingredient's supporting, not primary, role in the formula.
💡 Worth knowing: this ingredient rounds out the formula's neurotransmitter support claim alongside its more prominent nitric oxide ingredients.