Ferritin(FER) Determination Reagent(Immunoturbidimetry) is an in vitro diagnostic quantitative test kit. Ferritin is a protein that holds iron in your body. Low ferritin levels can lead to iron deficiency anaemia, which occurs when your body does not have sufficient iron to produce haemoglobin, a type of protein in your red blood cells that carries oxygen. This can cause fatigue, weakness, shortness of breath, headaches, dizziness, and pale skin. Iron deficiency anaemia can cause heart problems and other complications in severe cases.