Heavy metal that in its trivalent oxidative states (3+) has a great nutritional value since it acts as a trace element (trace element) that enhances the action of insulin and is involved in the metabolism of carbohydrates, fats and proteins. Meat, seafood, brewer's yeast, whole grains and nuts (especially walnuts), among others, are very rich in chromium. The recommended intake in nursing mothers is 45 micrograms daily (Ares Segura 2015). The average concentration of chromium in breast milk is 1 nanogram / mL, ranging between 0.2 and 7 ng / mL and is independent of plasma levels and maternal daily intake (Kumpulainen 1980, Anderson 1993, Mohamedshah 1998). With a varied and balanced diet not mineral supplements are needed. Excessive intake of chromium can cause skin problems in infants (Adachi 2007). No increased concentrations of chromium in milk or problems in breastfed by mothers with hip containing chromium in its composition (Nelis 2013, Oppermann 2015) Not to be confused with states hexavalent (6+) industrial and irritating, toxic and carcinogenic effects (see tab chromic acid or chromium trioxide).