<span>Vitamin D.
Vitamin D is made from 7-dehydrocholesterol and needs UV light in order to be activated. Because the children are not exposed to sunlight, they are receiving insufficient UV light.</span>
Olivine, pyroxene, amphibole, mica, and quartz
The main reason that most farmers use stem cuttings rather than just planting a seed is that a tree's genetic variation will occur. The seeds of many fruit trees tend to vary differently from the parent, because seeds themselves are produced by sexual reproduction (i.e they receive genes from a male and female to form). As they are a cross from two sets of genes, many fruit trees are not “true to seed”. Their seeds will produce a generally different variety of tree from the parent. When using stem cuttings, it's almost like a cloning process.
