My, I certainly have to beat this out of you 🙂
Its well known that reduced sunlight exposure reduces the amount of vitamin D synthesized. However, severe vitamin D deficiencies have been abserved in healthy populations of girls in developed nations (G Das1, S Crocombe2, M McGrath1, J L Berry3 and M Z Mughal2)
Vitamin D deficiencies are higher among poor, urban, non-white adolescent girls everywhere. ALL of those factors contribute, so its stupid to make an argument relying only on dress when those factors have not been comprehensively addressed.
Lastly, this whole deal is stupid becuase such 'deficeincies" can be corrected by nutritional supplements or by proper nutrition.