Don't know about food, but natural sunlight is the best. Morning sun is best from what I've heard and read. I walk 30-60 minutes every day, usually morning or around 11am, still take 10,000IU of vitamin D3 daily, any excess D is pissed out.
Thanks dude... I also try to walk in the morning time in sunlight. Really this will surely help me to keep my body healthy and strong.