Vitamin D Synthesis and Water
To what degree does being in the water affect your ability to synthesize vitamin d from the sun? For example going to an outdoor pool and swimming laps. I know that it has to be limited to a degree, but by how much? Am I getting any vitamin d while I am in the water?
I don't know if anyone knows the answer to this question (meaning, I don't think there have been any studies done.) There was a study (or 2) of Hawaiian lifeguards and surfers and the surfers had lower vitamin D levels than the lifeguards. I think it may be more a matter of the water (or showering) washing off the oils on your skin where a lot of the D is hanging out after it is synthesized. Dr. Mercola recommends washing without soap (except for the necessary bits!) for 2 days after sun exposure. I have no idea what effect chlorine has on D synthesis, if any.
I wouldn't count on this for your only sun exposure, if that's how you plan on getting your D--but that's just a gut feeling. Best to get your levels checked and see if your sun exposure is sufficient or if you need to supplement.
That all makes sense, the effect of chlorine would be an interesting component to look into more.
I was mainly asking out of curiosity, I was in the pool yesterday and the thought passed through my mind. I am looking forward to spring when my work takes me outside more, and I can actually get a decent amount of sunshine during the week, instead of having to wait for the weekend to play in the sun!