Chapter 1 Literature Review
CHAPTER 1
Introduction
During the past decades Vitamin D deficiency had become a major health concern among many Asian countries. Even countries where the sun shines all year round Vitamin D deficiency is still prevalent. This problem is attributed to the dietary factors, inadequate exposure to sunlight and skin pigmentation among Asian people. In terms of skin pigmentation, the majority of Asian inhabitants have highly pigmented skin. Although high skin pigmentation it is generally beneficial because pigmentation reduces the penetration of ultra-violet rays it can also reduces the production of building blocks required to produce Vitamin D. In Saudi ...