|Vitamin D plays a necessary role in bone health by raising the absorption of bone building metallic element from the internal organ, supporting growth and maintenance of the skeleton, control levels of metallic element within the blood. Low vitamin D levels will cause bone and joint pain, increase the chance of falls and bone fracture in older individuals, end in rachitis (when terribly serious), impact on unhatched youngsters in mothers with vitamin D deficiency. The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.