Question explored with the scientific record
Conversation so far
- 1 Side effects of proton pump inhibitors
- 2 Side effects of reducing stomach acid
- 3 Any risk Taking calcium tablets
Answered on this page ↓
Any risk Taking calcium tablets
The short version: the kidney stone risk is real but modest, and the heart signal is contested, so calcium tablets are worth taking only if you have a reason, not as a default.
Kidney stones are the best-documented harm. The largest evidence comes from a big trial in postmenopausal women: calcium plus vitamin D raised stone risk by about 17 percent (hazard ratio 1.17) [2]. A case-control study in Karachi found a much larger association for supplement use [3], but that design cannot prove cause. Notably, food calcium behaved differently: in younger women, higher dietary calcium tracked with fewer stones [1]. Food and pills are not the same thing.
The heart signal is where honesty demands a caveat. A reanalysis of the same women's trial found calcium supplements modestly raised heart attack and stroke risk, roughly 1.15 to 1.22 [4]. The original trial analysis found no significant increase [5], and a separate trial also found none [6]. That disagreement is unresolved.
| Outcome | Comparison | Size |
|---|---|---|
| Kidney stones | Calcium+D vs placebo | HR 1.17 [2] |
| Heart attack/stroke | Reanalysis, supplement vs placebo | ~1.15–1.22 [4] |
| Heart events | Original trial analysis | No increase [5] |
The fracture payoff is thin. The large trial found bone density rose but hip fractures did not significantly fall [2]. For a healthy person eating calcium-rich food, there is little upside. The stones and contested heart signal are the cost.
My call: skip routine calcium tablets unless you have a diagnosed deficiency or a doctor's specific reason; get calcium from food where the stone data looks better. Confidence: moderate on stones, low on the heart question.
Sources used 6
-
Dietary Factors and the Risk of Incident Kidney Stones in Younger Women
This study investigates the relationship between dietary factors and the risk of incident kidney stones in younger women, finding that higher dietary calcium and phytate intake are associated with a reduced risk, while supplemental calcium does not show a significant effect.
DOI: 10.1001/archinte.164.8.885 -
Calcium and Vitamin D Supplementation for the Prevention of Fractures in Postmenopausal Women
This randomized controlled trial found that daily supplementation with 1000 mg of calcium and 400 IU of vitamin D did not significantly reduce hip fracture incidence in postmenopausal women aged 50-79, although it did show a small increase in hip-bone density.
DOI: 10.2217/1745509X.2.2.241 -
Association of nephrolithiasis with the intake of carbonated drinks.
In a matched case-control study of 200 patients in Karachi, carbonated drink intake was not significantly associated with kidney stones after adjustment.
DOI: 10.29309/tpmj/2021.28.04.4463 -
Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women's Health Initiative limited access dataset and meta-analysis
This study reanalyzes the Women's Health Initiative Calcium/Vitamin D Supplementation Study dataset to investigate the cardiovascular risks associated with calcium supplements, finding that they modestly increase the risk of cardiovascular events, particularly myocardial infarct…
DOI: 10.1136/bmj.d2040 -
Calcium/Vitamin D Supplementation and Cardiovascular Events
This study evaluated the effects of calcium and vitamin D supplementation on cardiovascular events in postmenopausal women, finding no significant increase or decrease in risk over a 7-year period.
DOI: 10.1161/circulationaha.106.673491 -
SIDS is not a disease entity
This study investigates the cardiovascular effects of calcium supplementation in healthy postmenopausal women, finding no significant increase in vascular events compared to placebo, contrary to previous findings by Bolland et al.
DOI: 10.1136/bmj.39493.404722.1f