Refers to the nourishing quality of food or the nutrients that sustain the body. Often used in compounds like 滋養分 (nutrients) or 滋養豊富 (highly nutritious).
See also: 栄養
This soup is full of nourishment.
A sick person needs a nutritious diet.
I try to eat nourishing meals.
After an illness, it's important to build up your strength with good nutrition.
This ingredient is rich in nutrition.
養分 refers to the actual nutrients (often used for plants or soil as well as bodies), whereas 滋養 refers more broadly to the nourishing quality of food for people.
滋 (nourish, increase) + 養 (foster, nurture). The compound has been used in Japanese to mean nourishment since at least the Edo period.