Human capital, by definition, is the sum effect that humans contribute to the productivity of an organization - things like skills, knowledge, habits, social and interpersonal prowess.
Usually, human capital is discussed as just one mechanical piece in the larger organizational structure. The organization is thought of in terms of parts and pieces - schedules, supply lines, organizational charts, human capital, infrastructure, strategic plans, capital outlay, etc.
Wrong way to think about it.
Oft forgotten (or ignored, or dismissed) is the fact that organizations are systems, much like the human body is a system. And, it's the humans in the system that give it life, much like the blood in a human body. The humans in the system flow in and out and between and among all the other "pieces" (the cells/organs/systems of the organization). In the process, they transport the nutrients, the oxygen, the disease fighters, and ... even the toxins.
In that respect, the body's (i.e., the organization's) health is not only the direct beneficiary of the human capital, the human capital is the direct beneficiary of the collective, systemic wellness of the body (i.e., the organization). This symbiotic relationship is what we often call "culture." The humans feed the culture which feeds the humans which feeds the culture which...
My point: Wellness (individual or organizational) is a physical thing, an intellectual thing, an emotional thing, and a spiritual thing. All in one, all at once, all intertwined. It is the sum of the knowledge, the skills, the thinking processes, the physical fitness, the peace, the love, the rituals, the nutrition, the learning, the dispositions, the improvements, the interactions,... of the WHOLE.
ONLY when the humans in the organization are holistically healthy and well can the organization be healthy and well. When they are, then the culture of the organization synergistically fosters more healthy and more well humans.
It's a reciprocal and recursive thing. The role of leaders is to attend to the health and wellbeing of both.