Furthermore, there was a significant additive interaction between lowest tertile of both handgrip strength and vitamin D and APOE e4 carries that associated with dementia among women (RERI: 2.868, 95% CI 1.048–4.688; AP: 0.352, 95% CI 0.169–0.537; SI: 1.671, 95% CI 1.175–2.375) and men (RERI: 2.020, 95% CI 0.460–3.581; AP: 0.262, 95% CI 0.085–0.439; SI: 1.431, 95% CI 1.069–1.915. This evidence concerns the gene APOE and dementia.