Nordion Inc. is a health science company that provides products used for the prevention, diagnosis and treatment of disease. The company supplies sterilization technologies and medical isotopes to customers in more than 40 countries around the world.

MD, Md, mD or md may stand for:

• Doctor of Medicine, from the Latin Medicinae Doctor (MD)
• Mean difference, a measure of statistical dispersion
• Md, the symbol for the chemical element Mendelevium
• Mesoscale Discussion, a short-term technical meteorological forecast concerning convection (MCD) or precipitation (MPD)
• Methyldichloroarsine, a blister agent used in chemical warfare
• Millidarcy (mD), one thousandth of a darcy, a unit of fluid permeability
• Molecular dynamics, a method of computer simulation of molecular interaction
• Muscular dystrophy, a genetic and hereditary muscle disease
• Medial dorsal nucleus, a large nucleus in the thalamus

MDS or M.D.S. may refer to:

Companies and organizations

• The Brazilian Ministry of Social Development
• MDS Inc., a global health and life sciences company
• MDS America, a global telecommunications company
• Media Design School (New Zealand), a media industry tertiary training institution
• Mennonite Disaster Service, a disaster relief volunteer group
• Meridian Southern Railway
• Microwave Data Systems, a wireless modem company
• MDS Gateways, a telecommunications company based in Ireland
• Movement for Socialist Democracy (Mouvement pour la Démocratie Socialiste), a former political party in Burkina Faso
• Movement of Socialist Democrats (Mouvement des Démocrates Socialistes), a political party in Tunisia