A year ago I was reading a bunch of papers on biofortification via plant breeding and there was some really interesting info about just how many people can be shifted from inadequate to adequate intake of some nutrients just by breeding in things like higher levels of lysine, zinc, iron, beta carotene, etc.. into staple crops. In places like india and africa just replacing a handful of crops with improved varieties can shift hundreds of millions of people out of deficiency ranges that cause permanent cognitive and physical stunting/disability.
Overtime as trace mineral depletion continues in global cropland and as CO2 levels reduce nutrient density of crops purposeful breeding programs and soil repletion will be necessary to have decent health of previous generations
https://static-content.springer.com/esm/art%3A10.1038%2Fs43016-022-00573-0/MediaObjects/43016_2022_573_MOESM1_ESM.pdf
supplement is good for getting more detailed ideas of what various scenarios look like for particular countries