Sulfur is widely distributed in nature. It is found in many minerals and ores, e.g., iron pyrites, galena, cinnabar, zinc blende, gypsum, barite, and epsom salts and in mineral springs and other waters. The metabolism of sulfur amino acids, methionine and cysteine, has been linked to several key aspects of human health and cellular function.

Food source
Sulfur is found in garlic and onions.

Use
Elemental sulfur is used in black gunpowder, matches, and fireworks; in the vulcanization of rubber; as a fungicide, insecticide, and fumigant; in the manufacture of phosphate fertilizers; and in the treatment of certain skin diseases.

Medical uses
Dr Oz's talked about it in his December 2010 show. He said sulfur comes from the Paricutin Volcano in Mexico. The Paricutin Volcano erupted for the first time in the1940's. He said sulfur is great for treating eczema, acne and wrinkles. Before we had antibiotics, we use sulfur to treat infections. Bryce Wylde said that just like you squeeze a lemon over a fruit salad to preserve it so that it does not age or rust - we too age and "rust" so sulfur helps to preserve us. One great way to treat yourself is by taking a sulfur bath.

Sulfur and bad breath
Sulfur containing foods may cause bad breath, otherwise known as halitosis.

J Vet Dent. 2015 Summer;32(2):99-102.The Negative Effects of Volatile Sulphur Compounds. Oral malodor has been studied extensively in humans but not necessarily to the same degree in our veterinary patients where malodor constitutes a significant problem. Breath malodor may originate from the mouth, or from an extra oral source, originating from other organ systems such as gastrointestinal, respiratory, or even systemic disease. Oral malodor is a result of microbial metabolism of exogenous and endogenous proteinaceous substrates leading to the production of compounds such as indole, skatole, tyramine, cadaverine, puterescine, mercaptans, and sulphides. Volatile sulphur compounds have been shown to be the main cause of oral malodor. Although most clients perceive oral malodor to be primarily a cosmetic problem, there is an increasing volume of evidence in human dental literature demonstrating that volatile sulphur compounds produced by bacteria, even at low concentrations, are toxic to tissues and play a role in the pathogenesis of periodontitis.

Sulfur in onions and tears
Onions contain sulfur. When onion cells are broken, they release sulfur in the air which react with moisture in eyes forming sulfuric acid. The sulfuric acid causes a burning sensation. The eye creates tears to dilute the sulfuric acid to protect the sclera and the cornea from the acid.

Sulfur in plants
Sulfur-containing defense compounds are crucial for the survival of plants under biotic and abiotic stress. These sulfur compounds include elemental sulfur (S(0)), H(2)S, glutathione, phytochelatins, various secondary metabolites and sulfur-rich proteins. Their constitutive and/or stress-induced formation is intimately dependent on demand-driven sulfate uptake and assimilation.

Sulfur dioxide
Sulfur dioxide is a colorless gas with a suffocating, choking odor. It is toxic to humans and concentrations as low as 10 ppm will produce coughing. Sulfur dioxide is used as a bleaching agent, disinfectant, and refrigerant.