Is it possible that a person has a very low calcium intke through food (avoiding dairy) but has a normal blood calcium level? Furthermore, is it possible that supplementing calcium for this person improves a variety of stuff (like palpitaations and junk) despite blood level being solid, as calcium level is said to be carefully monitored by the body?
Serum calcium is not a reliable indicator of calcium status on it’s own. While you’re correct that the body monitors calcium status, this isn’t necessarily reflected in serum levels.
When a calcium deficiency exists (or bones are actively demineralizing - e.g. osteoporosis/hyperparathyroidism), calcium is leached from bones and ends up in the bloodstream. This can show up as normal serum calcium levels despite underlying issues directly influencing calcium status.
>…is it possible that supplementing calcium for this person improves a variety of stuff (like palpitaations and junk)…
This suggests to me that there’s probably an underlying deficiency, as palpitations can be just as much a symptom of calcium deficiency as they can be a symptom of hyperglycemia.
If a patient approached me with this concern, I would recommend a visit to their provider to request labs.