Part of methionine, cysteine, glutathione, connective tissue and many proteins.
No separate Swiss reference value; needs are met through sulfur-containing amino acids.
Protein-rich foods plus garlic, onions and cruciferous vegetables.
No isolated sulfur deficiency is defined when protein intake is adequate.
Problems more likely reflect general protein/amino-acid undernutrition or a specific metabolic disorder.
Hair and nails contain sulfur-rich proteins but do not reliably indicate isolated sulfur deficiency.
Severe protein malnutrition.
Assess protein intake and the overall clinical state.
No separate sulfur supplement is needed; balanced protein sources meet needs.
Supplement claims for MSM or “detox” are not equivalent to essential sulfur requirements.