а на это аргументируют этим, если по-русски вверху Вам не понятно было и Вы луче по английски понимаете:

Many will dispute this recommendation as "conventional" thinking teaches that vitamin D is formed in the skin, but this research is based on Dr. Michael Hollick's work, which is over 25 years old. New evidence suggests the current view on how vitamin D is formed is inaccurate. At this time no one has ever tested whether vitamin D is formed in human sebum, the fat that your skin produces. The only study that supports that vitamin D3 is formed in the dermal epidermal junction was done in humans where the sebum was removed from the skin.

Humans make some vitamin D on the surface of their skin, which water washes off. How much humans make on the surface and how much inside the skin, no one knows.

как видите, никто точно не знает, а Вы наверное карты таро перед этим скинули или в стеклянный шар заглянулi