Sulfur is the seventh most abundant element in the human body, it has been estimated that the total amount of sulfur in the body of a reference male of 70 kg is about 140 g.¹  Sulfur is present in the composition of two amino acids (SAA, sulfur amino acids), methionine (Met) and cysteine (Cys). Humans are unable to produce Met and Cys de novo and require the intake of both from dietary sources. Met is one of the nine essential amino acids in humans while Cys is considered conditionally essential since it is usually produced in the necessary amounts via the metabolism of Met. The sulfur amino acids are the primary sources to incorporate sulfur in a vast array of molecules, many of which are key metabolic intermediates.