On human nutrition, Boron (B) is classified in the category of possible essential elements; this means that its essentiality has not been proven and various causes have prevented it. The objective of this review was to analyze the next five causes that have possibly prevented to demonstrate the essentiality of B in humans: (1) Low daily requirement of B; (2) High number of sources to supply B in diet (3) Short life expectancy of humans (LEH); (4) Lack a method to diagnose B in vivo and; (5) Lack an area with low intake of B. Because the requirement of B in humans is very low (1.0 mg day -1 ), in trials of nutrition all sources of B should be controlled. Because a deficiency of B inhibits the synthesis of the active form of vitamin D, known as Calcitriol (1,25-(OH) 2 -D 3 ) and assimilation of Ca on humans, osteoporosis (OST) and arthritis (ART) could be diseases associated with a deficit of B. In the past, the short LEH (47 years) prevented that OST and ART were identified as symptoms of B deficit; however today the LEH is 73 years, under this situation, is possible that the mineral reserve on bones is not sufficient to ensure the properly body function, therefore incidence of OST and ART on the population could be increasing, especially in areas with low intake of B. On the other side, B hair analysis is a usefully diagnostic tool which could be used in experiments to demonstrate B essentiality on humans; these experiments should be conducted in areas where the population has low intake of B along with high incidence of OST and ART.