Yes. Being a hermit and having lived in Scotland for a most of my life I had a chronic vitamin d deficiency. It took me years to get to optimal levels. I've underwent an actual treatment where I took intramuscular injections. Also moved to LA where my sun exposure increased by orders of magnitude.
I'm a bigger proponent for agroforestry than other methods. Being that monocultures are the biggest catalyst of desertification, agroforestry, when implemented in industrial agricultural settings, has a higher dimensionality/impact.