Softening of bones that is often caused due to vitamin D deficiency is referred to as osteomalacia. Osteomalacia is different from that of osteroporesis, a disorder that may lead to bone fractures. Osteomalacia symptoms may not be seen in the initial stages, as it worsens individuals may experience muscle weakness and bone pains. The causes may be either deficiency of calcium and phosphate minerals which are required for strong bones or if the body does not absorb these minerals from the diet. If sunlight deficiency is the cause then replenishing the low levels of vitamin D may cure osteomalacia. If calcium or phosphorous are in low quantities in blood then supplements containing those minerals may be used for curing the disorder. Review articles are the summary of current state of understanding on a particular research topic. They analyze or discuss research previously published by scientist and academicians rather than reporting novel research results. Review article comes in the form of systematic reviews and literature reviews and are a form of secondary literature. Systematic reviews determine an objective list of criteria, and find all previously published original research papers that meet the criteria. They then compare the results presented in these papers. Literature reviews, by contrast, provide a summary of what the authors believe are the best and most relevant prior publications.