MAPT and Alzheimer disease: To address this research gap, we investigated the associations between serum levels of essential trace elements (Mn, Fe, Co, Cu, Zn, Se, and Mo) and serum levels of AD biomarkers (Aβ42, the Aβ42/Aβ40 ratio, p-tau181, and total tau) in 189 midlife women from the Study of Women’s Health Across the Nation (SWAN) at the Michigan site.