Welcome to the fourth part of our ‘Minerals that help trigger sleep’ series.
Today, we look at our third trace element- Iron also known as Fe.
What is the link between iron and sleep?
Iron is a metal and trace element that is one part of haemoglobin- the protein that makes oxygen bind to red blood cells. Iron is needed for respiration as well as metabolism and muscle repair.
Your body cannot make iron so it relies heavily on absorbing iron from iron-rich foods. If your diet is low in iron, then your body will utilise iron from its own iron stores (called serum ferritin). Once these stores are depleted, you will become iron-deficient as there will no longer be enough iron available in your body (this is called anemia).
Testing for iron-deficiency and diagnosing anemia is based on medical history as well as blood tests.
A study by Lee et al (2004)
'Restless Legs Syndrome and Sleep Disturbance during Pregnancy: The Role of Folate and Iron' showed that mothers who experience these involuntary movements at night and go on to experience poor sleep have both reduced serum folate and serum ferritin levels. Iron supplementation made a huge difference in these mothers symptoms and improved their sleep quality.
What foods are rich in iron?
There are two forms of iron found in food- heme and non-heme. Plants and fortified foods contain non-heme iron, whilst meat and animal protein foods contain heme iron. Foods that are rich in non-heme iron are nuts, beans and vegetables.
Foods that are rich in heme iron include lean meat and seafood as well as dairy, eggs and fish.
Breastmilk contains highly bio-available iron, but this becomes insufficient from 4-6 months. It is usually at this time that babies start eating fortified cereals, meat and vegetables to meet their increasing iron needs. Babies who do not have access to these foods may go on to become anemic.
For more specific values see the iron-rich food list here.
What supplements can be taken?
Those at risk of iron-deficiency include premature babies who are born before they have accumulated a sufficient iron store; young children; senior citizens; women who are menstruating; women who are pregnant and breastfeeding and those who cannot/do not eat enough animal protein.
Iron supplementation can be complex as there are many different products on the market and their bio-availability differs. Most multi-vitamins designed for women contain the recommended daily dose.
However, for those with confirmed iron-deficiency they will need to complete a six month course of iron supplementation to build up their ferritin levels.
As vitamin B12 is required for iron to be taken up out of food, often vitamin B deficiency may pre-date iron deficiency and so vitamin B supplementation is also required.
If there is iron-deficiency despite a varied diet, it is likely that the gut is not absorbing nutrients correctly. In this case both vitamin B and iron may need to be given intravenously, that is directly into the bloodstream.
What precautions need to be followed?
Too much of anything is not good for you. Taking too many iron supplements will result in nausea and constipation. Intravenous iron and vitamin B supplementation needs to be monitored by a doctor.