Though iodine was among the first nutrients recognized as vital to humans today, deficiency affects 780 million people worldwide. While other nutrients, like zinc, are derived from the parent materials of the soil (minerals and organic material transported by water, ice, wind, etc. that make up soil) the majority of iodine in soils is derived from the atmosphere and ultimately, the oceans. But the organic content, texture, oxidation and pH condition of the soil (which parent material does have a role in) determines retention and concentration of iodine.