My skin is very dry and sensitive towards sun. Skin is mostly dehydrated and rough and is showing fine lines on forehead and under eyes since I was 24 . Skin is thin with lost elasticity. And usualy not glowing . Feels little shaggy. In  summers chicks  gets oily and pores have little widened. I use olive oil for massage and have  never ever gone under any chemical treatment for skin .  Calcium deficiency is a general health issue with me where as periods are regular with lesser flow . Skin is not pron to pimples and generally is clear . Kindly explain the reasons and remedy.