Manganese is a trace element that is needed in the body and a healthy adult will have around 12 – 20 mg of it in their body 1. It is needed for healthy bone development as well as in the production of the hormone thyroxine.
Manganese is absorbed as Mn 2+ ions. Deficiencies of it in the diet are rare but may manifest themselves in conditions such as poor bone development or the slowed growth of hair and nails. A good source of manganese comes from eating green leafy vegetables as it is involved in photosynthesis.
Manganese is also toxic if too much of it is absordbed into the body. This would have to be due to drinking contaminated water or breathing in contaminated dust. You will not absorb too much manganese from eating too many greens in your diet! Signs of manganese poisoning include Parkinson’s disease type symptoms.