Sunlight
I believe one of the greatest disservices the dermatology profession has done to the world has been to spread an immense fear that the sun causes skin cancer (even though the most dangerous skin cancer, melanoma, is linked to a lack of sun exposure). This appears to have come about because the dermatology profession reinvented themselves as cancer fighters (which pays a lot), and part of establishing that cultural belief system revolved around neurotic rituals to avoid all sunlight. I think this is quite sad, because avoiding sunlight significantly increases your risk of death from many different cancers (and overall has a danger of the same magnitude as smoking).
One of the major misunderstandings about sunlight is that its only benefit is vitamin D production. Instead, it has a variety of other ones as well, including:
•Producing cholesterol sulfate.
•Producing nitric oxide.
•Directly creating liquid crystalline water.
Note: I have long wondered if some of the benefits attributed to vitamin D are actually due to it being correlated with the above three occurring.
Since sulfates are used by the body to create liquid crystalline water and maintain the physiologic zeta potential, this function is very important. Since cholesterol sulfate primarily resides in cell membranes (where it is recognized to have a "stabilizing role" for the cell membrane), it provides the critical role of coating the cell with sulfates.