I like vitamin D. With that said I have't tested my D levels in awhile. The last time I did I was around 60ng/ml. I'm likely still around the same level.
Of late I've found different light therapy ideas beneficial. As an example, I've been enjoying using a SAD light in the morning to help wake up. Reportedly SAD lights boost different hormone levels, help with depression and increasing energy. I've found that to be the case with me, with my colitis condition.
As an example, and a different topic somewhat, the recently article I recall seeing is on testosterone and libido levels being boosted by a SAD light box. I've seen written mentions of other hormones being boosted by light therapy also.
"Bright light boosts testosterone in men with low libido, study says"
http://www.latimes.com/science/sciencenow/la-sci-sn-bright-light-libido-20160919-snap-story.html
excerpt:
For men whose sex drive has stalled, Italian researchers have found in a small study that early morning exposure to bright light – a treatment widely used for seasonal depression -- revs up testosterone production and boosts sexual function and satisfaction.
In a pilot trial that recruited 38 men diagnosed with problems of sexual desire and arousal, researchers at Italy’s University of Siena found that after two weeks, participants who spent a half-hour each morning in front of specially designed light box experienced increases in testosterone and a three-fold improvement in sexual satisfaction. Participants who were randomly assigned to get a placebo treatment – a light box that delivered a level of light only 1% as intense – saw no significant change on either measure....