| RCIT | red cell iron turnover |
|---|---|
| RCITR | red cell iron turnover rate |
| SI | International System of Units [Fr. le Systeme International d'Unites]; sacroiliac; saline infusion; ... |
| SID | single intradermal [test]; Society for Investigative Dermatology; sucrase-isomaltase deficiency; sud... |
| SIDS | sudden infant death syndrome; sulfo-iduronate sulfatase |