It was wintertime and I knew that he works indoors mostly. I suspected he was experiencing vitamin D deficiency due to lack of sunlight, which would be a contributing factor to a compromised immune system. On top of this, from what I gathered, he had a less than optimal diet because he had been doing a lot of traveling. I had some vitamin D with me so I thought it would be the perfect time to see if it was as effective as I had read.I wasn’t worried about any danger of it reacting with any of the medicines he…