Last week i very briefly mentioned that i am taking iron supplements on the advice of my doctor, this is due to an episode of extreme fatigue, lethargy and what i can only describe as pure exhaustion. After blood tests it was deemed my iron levels were below what they should be and it had begun to have an impact on my haemoglobin so i was prescribed iron supplements to help boost my levels. Because of this, i felt a focus on iron as my first (hopefully) informative blog post would be the best place to start.
Iron (Fe) : Mineral : Atomic Number 26
The most abundant form of iron in the human body, and probably its most wildly known use, is haemoglobin. It is haemoglobin that transports oxygen around the body to all the cells to allow them to function.
Consumed dietary iron comes in two forms, Heme and Non-Heme, these are absorbed in the body using different mechanisms. As a rule, foods of animal origin contain a higher level of non-heme to heme iron whilst plant foods only contain heme iron. Heme iron is easily and well absorbed by the body, the absorption of non-heme iron is dependant on other vitamins and minerals consumed at the same which are needed to promote the non-heme iron absorption and also on the iron stores of the individual. If stores are depleted, the body will aim to absorb as much non-heme as possible but adequate stores and the body will require enhancing substances from other foods to promote absorption.
Iron deficiency is the most common nutritional deficiency in the world and is broadly known as anaemia but can be categorised by different types of anaemia. Generally speaking anaemia is a reduction in the oxygen-carrying capacity of blood due to a reduction in the number of red blood cells or a decrease in haemoglobin in the blood.
Iron levels are indicated via blood test and initially it is ferritin serum levels that are measured as these are the first detectable storage levels of iron to decrease which indicate the beginning of the onset of anaemia.
Iron deficiency anaemia is the type of anaemia most susceptible to dietary changes however nutritional deficiencies is not the only factor for onset. Common symptoms of iron deficiency anaemia include, but are not limited to:
- tiredness/low energy
- pale complexion
- shortness of breath
- feeling cold
Risk factors for iron deficiency anaemia can include:
- low iron dietary intake
- menstrual blood loss
- excessive blood loss
- gastrointestinal issues
UK dietary reference values (DRVs) for iron intake according to the largest age bracket and by sex:
19-50 year old male = 8.7mg/d
19-50 year old female = 14.5 mg/d (50+ year old female = 8.7mg/d due to expected cessation of menstruation)
Dietary Sources and Food Combinations-
Good dietary sources of heme iron include all meat, fish and animal origin produce, with calfs liver, chicken eggs and red meats having marginally higher quantities.
Non-heme iron sources include whole wheat flour and dark green leafy vegetables such as spinach.
To aid absorption of non-heme iron, ascorbic acid or Vitamin C has been shown to improve uptake. Incorporating vitamin C contains vegetables or fruits such as bell peppers, kiwi or oranges into meals with non-heme iron sources will help the body utilise the available iron. Also, if increasing intake with iron supplements, taking them with a small glass of fruit juice or alongside a piece of fruit will aid absorption.
Tannins which are commonly found in tea inhibit absorption of available iron so it is recommended to avoid drinking tea with meals or soon after so as not to diminish the uptake of iron.
I hope you have found some interesting information in this blog post and as always in science and nutrition, the detail could spill on and on for hours regarding the knock on effect and impact on the body that micronutrient deficiency can cause. I have done my best to include a little bit of knowledge and know how surrounding iron intake but would love to hear any feedback you have. Im happy to answer any questions but be aware i am not a registered medical professional and seeking advice from you doctor or a registered dietician/nutritionist is always the best course of action for any serious medical queries.
Department of Health, (1991), Dietary Reference Values for Food Energy and Nutrients for the United Kingdom, Norwich:TSO, pp.161-166.
Strain, JJ and Cashman KD, (2009), Minerals and Trace Elements. In: Introduction to Human Nutrition, 2nd ed. Chichester:Wiley-Blackwell, pp.205-209.
Tortora, GJ and Derrickson, BH, (2009), Principles of Anatomy and Physiology; Maintenance and Continuity of the Human Body. 12th ed. Hoboken:John Wiley & Sons, pp. 711.
World Health Organisation, (2017), Iron deficiency anaemia [online], Available at: http://www.who.int/nutrition/topics/ida/en/ [Accessed 21 March.2017].
Zijp, IM., Korver, O and Tijburg, LBM, (2000), Effect of tea and other dietary factors on iron absorption, Critical Reviews in Food Science and Nutrition, 40(5), pp371-398.