Safety · Supplement
Calcium: side effects, safety & interactions
Constipation and, at high supplemental doses, kidney-stone and possibly cardiovascular concerns. Prefer dietary calcium
- Overall grade
- Grade B
- Last revised
- 0
- graded outcomes
- 0
- references listed
Assembled by the app from other entries in this library. It adds no evidence of its own — follow the links to the entries it draws on.
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Watch with Iron: Blunts iron absorption — separate.
The evidence in words
Safety profile
Constipation and, at high supplemental doses, kidney-stone and possibly cardiovascular concerns. Prefer dietary calcium and modest supplemental top-ups with D and K2.
Interactions to respect
Iron — Blunts iron absorption — separate. · Levothyroxine — Binds thyroid hormone — separate by 4 hours.
What Calcium is
Calcium is the most abundant mineral in the body, almost all of it in bone, with a small tightly-regulated pool doing signaling work. Requirements are usually met by dairy; supplements fill the gap for those who avoid it.
The honest bottom line
Cover calcium from food if you can. If you supplement, keep single doses small, pair with vitamin D and K2, and don't chase megadoses — bigger is not safer here.
Related reading
Entries that share this one's tags or conditions.
- Silicon: side effects, safety & interactionsSafe at supplemental doses.Evidence grade C
- Strontium: side effects, safety & interactionsCardiovascular-risk signal (from the ranelate data); interferes with calcium absorption and DXA interpretation.Evidence grade C
- Vitamin D: side effects, safety & interactionsVery safe in the ordinary range; toxicity (hypercalcemia) is real but requires sustained megadosing, typically well abovEvidence grade A
- Vitamin K2: side effects, safety & interactionsVery safe. The critical exception: K2 (like K1) antagonizes warfarin and other vitamin-K-antagonist anticoagulants — anyEvidence grade B
Sources
This entry lists no references of its own — it is assembled from the entries it links to, whose sources are on their pages.
Last revised . A grade is this entry's reading of the evidence, not medical advice.