A child’s endowment is a reflection of his/her genetic makeup and the conditions faced in early life. Parents build on their child’s endowment by investing resources in their child, and together, a child’s endowment and subsequent investments act as input into important later-life outcomes. A positive or negative shock to a child’s endowment can have a direct biological effect on a child’s long-term outcomes but may also affect parents’ decisions about investments in the health and human capital of their children. Using follow-up data collected several years after a randomized trial in Ghana, we explored whether maternal and child supplementation with small-quantity lipid-based nutrient supplements (SQ-LNS) throughout much of the first 1,000 days influenced parental investments in the health and human capital of their children. Across the domains of family planning, breastfeeding, health, education, and paternal financial support, we found that, in general, the intervention did not affect investments in the treated child nor his/her untreated siblings. These results suggest that given production technologies, constraints, and preferences, the intervention either did not change parents’ optimal investment strategies or that the effects of the intervention, namely increased birth size and attained length at 18 months of age, were too small for parents to perceive or to have any meaningful impact on parents’ expectations about the returns to investments in their children.