According to another research[1] vitamin D supplementation actually changes a lot of taken in adequate (by orders of magnitude higher than the official RDA) dos

According to another research[1] vitamin D supplementation actually changes a lot of taken in adequate (by orders of magnitude higher than the official RDA) doses regularly (and it also affects mood). So I conclude that what we need is to also supplement nitric oxide, not just vitamin D alone. I had never feared sun and don't even use sunscreens but I neither live in a particularly sunny area nor have enough spare time for regular sunbathing so supplements still are the only way to get enough. [1] https://news.ycombinator.com/item?id=15867918 https://news.ycombinator.com/item?id=15867918