MS and sunlight

Twenty years ago I remember a medical school lecturer mentioning that MS had a peculiar latitudinal distribution based on where a person grew up. The further north one went, the more common it was. I'm sure I wasn't the first person hearing that to think that there was some connection to sunlight exposure in early life.

Maybe there is ...

Vitamin D may lower risk of multiple sclerosis, study finds - USATODAY.com:

Among whites, those with the highest blood levels of vitamin D had a 62% reduced risk of developing the disease. The protection was the strongest for people who were younger than 20 — a finding that suggests that to be effective, a protective agent might need to kick in very early in life, Ascherio says...