Further subgroup analyses showed that low levels of calcium were significantly associated with a high risk of AKI in SAH patients aged ≥60 years (OR = 0.27, 95%CI: 0.09–0.83), who had GCS score ≥13 (OR = 1.57, 95%CI: 1.08–2.30), who did not use calcium channel blockers (CCB) (OR = 2.22, 95%CI: 1.16–4.25) and angiotensin-converting enzyme (ACE) inhibitors (OR = 1.51, 95%CI: 1.06–2.14), and who did not undergo aneurysm embolization (OR = 1.48, 95%CI: 1.01–2.17) and aneurysm clipping (OR = 1.45, 95%CI: 1.04–2.01). This evidence concerns the gene ACE and acute kidney injury.