Hi. Thank you Paul, Glenntaj and Mrs D for your response. I am confused as why the results came out low.

Winters in Mexico are different form those in the US, in Europe or Australia. We do receive the sun in the winter, specially where i live. I actually went to a beach in december which was very sunny and was sunbathing for some a week. I work indoors, so i am not normally exposed to sun on working days, but i am on weekends

As far as my skin, it is light no sooo light, but still light. I could say i am an averdage latine girl, with white skin and dark hair.

So i don't know why the vitamin d levels were low. Paul, thank you for the articles. I read them and i read others. If i am not mistaken, despite of not being officialy deficient i should do something about my vitamin d, because other literature considers 20ng/ml still very low.

Basically i am considering, getting extra sun exposure on winter days by doing exercise outdoors. I will have my levels re tested in two months, if i don't get any improvement i wil star supplementing.

An other question Paul. Why do you say that if you start taking supplements, then you should do it for life???

Thank you guys!