Digestive 
Blood
Cardiovascular
Dermatology
Genitourinary,
Hormones
Infections
Oncology and
Musculo-skeletal
Mental health and
Parasites
Respiratory
Senses
Various
Red blood cells are produced in red marrow, a tissue located inside of flat bones.
Healthy red blood cells live between 80 and 120 days. After that period, old blood cells are eliminated by the body.
The haemoglobin in red blood cells is the protein responsible for transporting oxygen. Each red blood cell contains hundreds of thousands of molecules of haemoglobin. People with anaemia do not have enough haemoglobin thus oxygen is not delivered well.
To produce red blood cells, the body needs certain vitamins, minerals and nutrients. Iron, vitamin B12 and folic acid are three of the most important.
