By Yvette Brazier. Last updated Thu 10 August 2017
Anemia is a common condition that results from a lack of certain vitamins and minerals. Not consuming a balanced diet can lead to a deficiency, or malnutrition.
Anemia affects over 30 percent of the world’s population. It is most severe among pregnant women and in children.
A range of health problems can arise from nutritional deficiencies. Nutritional deficiency anemia can lead to a low red blood cell count, low hemoglobin in the red blood cells, or red blood cells that do not function as they should.
Nutritional deficiency anemia mainly results from a lack of iron, but a lack of folate or vitamin B12 can also cause anemia, and a low vitamin C intake can contribute.
Nutritional deficiency anemia can happen because of a lack of nutrients in the diet or because of an illness or medical condition that make it hard to absorb nutrients.
Contents of this article:
Causes of deficiency anemia
Fast facts on nutritional deficiency anemia:
Here are some key points about nutritional deficiency anemia. More detail is in the main article.
Iron-deficiency anemia can happen when a person does not have enough iron in the diet, or if they have a condition that makes it hard to absorb nutrients.
It can lead to a low level of red blood cells.
Vitamin-deficiency anemia happens when a person does not consume or absorb enough vitamin B12, or B9, also known as folate.
It can cause red blood cells to be an unusual shape, so that they cannot function properly.
Nutritional deficiency anemia can affect a wide range of bodily functions.
The main way to treat or prevent it is through a healthful diet.
Anemia resulting from iron deficiency is considered one of the top 10 contributors to the global burden of disease. The World Health Organization (WHO) describe iron-deficiency anemia as “the most common and widespread nutritional deficiency in the world.”
In 2011, the WHO estimated that, globally, anemia affects 43 percent children up to the age of 5 years, 38 percent of women during pregnancy, and 29 percent of women who are not pregnant.
In iron-deficiency anemia, the red cells appear abnormal and are unusually small (microcytic) and pale (hypochromic). The pallor of the red cells reflects their low hemoglobin content.
A person with iron-deficiency anemia often has:
fatigue and lack of energy
shortness of breath
heart palpitations, or irregular heart beat
Other symptoms include:
changes to the sense of taste
a desire to eat ice, known as pica
sores or ulcers at the corner of the mouth
spoon-shaped fingernails and toenails
missed menstruation in women during their reproductive years
Iron-deficiency anemia is common in people who:
consume little iron in their diet
have a condition that prevents the body from absorbing nutrients
have a stomach ulcer, heavy menstruation, or another cause of bleeding
have a genetic disorder, such as sickle cell anemia or another health condition, such as malaria
Iron deficiency and diet
Iron-deficiency anemia can result from a lack of iron in the diet. During pregnancy, for example, women need more iron to supply the fetus. If they do not take in enough, this may lead to a dietary deficiency anemia.
Heme iron is the most bioavailable form of iron and is found only in meat. Non-heme iron is found in plant based foods and is not as easily absorbed. Vegetarians and vegans need to be mindful of their iron intake to ensure they are meeting their needs.
A lack of vitamin C in the diet can reduce the body’s ability to absorb iron, leading to anemia.
Iron-deficiency anemia can affect a person’s overall health and their ability to function at work and in their daily routine.
Vitamin-deficiency anemias can result from deficiencies in folate (vitamin B9) or vitamin B12.
When the intake of these nutrients is low, or if the body is not absorbing them properly, red blood cells may become too large or adequate amounts of red blood cells are not produced.
This is called megaloblastic anemia.
A person with vitamin-deficiency anemia may experience:
fatigue and lack of energy
tingling, or pins and needles
a sore, red tongue
depression and confusion
problems with concentration, thinking, and memory
Long-term complications include:
nervous system disorders, which may be permanent
infertility, which is usually reversible
heart problems, and possible heart failure
complications during pregnancy
congenital disorders in newborns
Causes of deficiency anemia
Some people have low levels of the necessary nutrients because of:
a low dietary intake of iron, vitamin B12, or folate, due, for example, to a vegan diet or a “monotonous, plant-based diet”
a low dietary intake of Vitamin C
a lack of intrinsic factor, a protein secreted by the stomach that aids in the absorption of vitamin B12
a health condition that makes it hard to absorb nutrients, such as celiac disease
a health conditions that makes it harder for the body to make enough red blood cells
medications, such as proton pump inhibitors (PPI), which affect the way the body absorbs vitamins
Riboflavin, and copper are also needed for the body to make red blood cells. If these are missing from the diet or if a person cannot absorb them, there is a higher risk of anemia. Other risk factors for anemia
Factors that increase the risk of anemia include:
problems with the hormone erythropoietin, which stimulates the bone marrow to make red blood cells
conditions such as kidney disease and cancer, which make it hard for the body to produce enough red blood cells
some cancer treatments that may damage the bone marrow or reduce the red blood cells’ ability to carry oxygen
damaged bone marrow, which cannot make red blood cells fast enough to replace the ones that die or are destroyed
Other factors that increase the risk of anemia include:
HIV or AIDS: Infections or medicines used to treat these diseases can lead to anemia. Pregnancy: During the first 6 months of pregnancy, the fluid portion of a woman’s blood, or plasma, increases faster than the number of red blood cells. This dilutes the blood and can lead to anemia. Alcohol consumption: This can affect the absorption of folate and vitamin B12, potentially leading to anemia. Aplastic anemia: Some people are unable to make enough red blood cells from birth. Infants and children with aplastic anemia often need blood transfusions to increase the number of red blood cells in their blood. Certain medicines, toxins, and infectious diseases, also can cause aplastic anemia.
Treatment for nutritional deficiency anemia is through a varied diet, including mineral-rich and fortified foods, and vitamin and mineral supplements, if appropriate.
The Dietary Guidelines for Americans 2015-2020 recommend the following daily intake of iron, folate, and B12.
Folate mcg DFE
Men 19-30 years
Women 19-30 years
Men 31-50 years
Women 31-50 years
DFE means dietary folate equivalent. This is used because folic acid and folate are absorbed differently in the body.
Fortified cereals are a good source of nutrients. The amount depends on the product and the manufacturer.
Vitamin C enhances iron absorption, while tannin, found in tea, reduces it. Consuming more vitamin C and reducing intake of tannin, therefore, can also help prevent anemia. Good sources of vitamin C include red peppers, oranges, strawberries, and broccoli.
While some causes of anemia require medical treatment, such as transfusions, the WHO estimated that in 2011, half of all cases of anemia in women could be solved through supplementation.
People who are at risk can take supplements orally or by injection. Those with severe deficiencies may need hospitalization, where they may receive the nutrients intravenously.
A person with B12 anemia may need injections of the vitamin once a month, or they may use a nose spray, a tablet under the tongue, or a tablet that is swallowed.
People with folate deficiency may need to take folate tablets.
If deficiencies result from an inability to absorb nutrients, supplements may be a life-long treatment.
During pregnancy, women may need to take supplemental iron and folic acid. A health care professional can advise about use of these supplements.
However, for most people living in developed countries, a healthful diet that meets the dietary guidelines for nutrients will normally provide enough iron, folate, and vitamin B12 to prevent anemia.
By Megan Ware RDN LD.Last updated Wed 3 February 2016
Iron deficiency anemia is the world’s most common nutritional deficiency disease and is most prevalent among children and women of childbearing age.
This type of anemia develops due to an inadequate amount of iron in the diet, impaired iron absorption, acute blood loss caused by hemorrhage or injury, or gradual blood loss such as from menstruation or gastrointestinal bleeding.
Inadequate intake of vitamin C can also contribute to iron deficiency as vitamin C is needed to absorb iron found in plant foods (non-heme iron).
Iron-deficiency anemia should not be confused with megaloblastic anemia which results from inadequate intake and/or utilization of folate and vitamin B12. Pernicious anemia is a form of megaloblastic anemia caused by a lack of a substance called intrinsic factor in the stomach that results in poor absorption of vitamin B12.
MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular vitamins and minerals. It provides an in-depth look at recommended intake of iron, its possible health benefits, foods high in iron and any potential health risks of consuming iron.
Contents of this article:
Possible health benefits of consuming iron
Foods high in iron
Potential health risks of consuming iron
The Recommended Daily Allowance (RDA) for iron depends on a person’s age and sex.
9-13 years: 8 mg
14-18 years: 11 mg
19 years and older: 8 mg.
9-13 years: 8 mg
14-18 years: 15 mg
19-50 years: 18 mg
51 years and older: 8 mg.
Pregnancy: 27 mg
Lactation 14-18 years: 10 mg
Lactation 19 years and older: 9 mg
An estimated 8 million women of childbearing age in the US suffer from iron deficiency severe enough to cause anemia. Iron deficiency during pregnancy may raise the risk for preterm delivery.
Iron supplements can be helpful where people find it difficult to achieve adequate iron status through diet alone. It is, however, preferable to try to achieve optimal iron status by including iron-rich foods in the diet and by removing or reducing factors that may hinder iron absorption. This is because many of the foods that are rich in iron also contain a range of other beneficial nutrients that work together to support overall health.
Possible health benefits of consuming iron
Iron deficiency can cause many health problems, including impaired cognitive function, gastrointestinal disturbances, poor exercise and work performance, lowered immune function and poor body temperature regulation.
Iron deficiency anemia and iron dysregulation are associated with conditions such as rheumatoid arthritis (RA) and Lupus Erythematosus.7
In children, iron deficiency anemia can cause psychomotor and cognitive abnormalities resulting in future learning difficulties.
Blood volume and red blood cell production increases dramatically during pregnancy in order to supply the growing fetus with oxygen and nutrients. As such, the demand for iron also increases. While the body typically upregulates iron absorption during pregnancy, insufficient iron intake or other factors affecting iron absorption or utilization can lead to iron deficiency.
Low iron status during pregnancy increases the risk of premature birth and low birth weight, as well as low iron stores and impaired cognitive or behavioral development in infants.
Not getting enough iron in your diet can affect how efficiently your body uses energy. Iron carries oxygen to the muscles and brain and is crucial for both mental and physical performance. Low iron levels may result in a lack of focus, increased irritability and reduced stamina.
Better athletic performance
Iron deficiency is more common among athletes, especially young female athletes, than in sedentary individuals. Iron deficiency in athletes decreases athletic performance and weakens immune system activity. A lack of hemoglobin can greatly reduce physical work performance as it decreases the body’s ability to transport oxygen to the muscles.
Foods high in iron
Iron has a low bioavailability, meaning that it has poor absorption within the small intestine and low retention in the body, decreasing its availability for use. The efficiency of absorption depends on the source of iron, other components of the diet, gastrointestinal health, use of medications or supplements, and a person’s overall iron status. In many countries, wheat products and infant formulas are fortified with iron.
There are two types of dietary iron – heme and non-heme. Most animal products, including seafood, contain both non-heme and heme iron, with the latter easier to absorb as it is bound to protoporphyrin IX. Non-heme iron sources include beans, nuts, vegetables and fortified grains.
The recommended iron intake for vegetarians is 1.8 times higher than for those who eat meat in order to make up for the lower absorption level from plant-based foods. The bioavailability of iron from omnivorous diets that include meat, seafood, and vitamin C is around 14-18%, while iron bioavailability from a vegetarian diet is around 5-12%.4,5 Consuming vitamin C-rich foods alongside non-heme sources of iron can dramatically increase iron absorption.
Non-heme iron absorption is inhibited by:
Proton pump inhibitors (lansoprazole [Prevacid®] and omeprazole [Prilosec®]) used to reduce the acidity of stomach contents
Polyphenols in cereals and legumes, as well as in spinach
Tannins in coffee, tea, some wine and certain berries
Phosphates in carbonated beverages such as soda
Phytates in beans and grains.
Both heme and non-heme iron absorption may be impaired by calcium. Typically, a varied western-style diet is considered balanced in terms of enhancers and inhibitors of iron absorption.
The tolerable upper intake level for iron is between 40-45 milligrams. Adults with a healthy functional gastrointestinal system have a very low risk of iron overload from dietary sources.
People with a genetic disorder called hemochromatosis are at a high risk of iron overload as they absorb three to four times more iron from food compared to people without the condition.8 This can lead to a build-up of iron in the liver and other organs, and the creation of free radicals that damage cells and tissues including the liver, heart and pancreas, in addition to increasing the risk of cancer.8
Around 10% of white people of Northern European ancestry carry the most common hemochromatosis gene (HFE) mutation (C282Y), but only around 0.044% of white people carry two copies of the mutated gene, resulting in hemochromatosis.8 People of other ethnicities are much less likely to have hemochromatosis.
Taking iron supplements of 20 milligrams or more on a frequent basis can cause nausea, vomiting and stomach pain, especially if the supplement is not taken with food. In severe cases, iron overdoses can lead to organ failure, coma, seizure, and even death. It is important to keep iron supplements out of reach of children so as to reduce the risk of fatal overdose.
Accidental ingestion of iron supplements were responsible for about a third of poisoning deaths among children in the US between 1983 and 1991, and some 43 deaths between 1983 and 2000.
Changes in the manufacture and distribution of iron supplements, such as replacing sugar coatings on iron tablets with film coatings, using child-proof bottle caps, and individually packaging high doses of iron have all helped to reduce accidental iron overdoses in children. Just one death from iron overdose was reported between 1998 and 2002.
Some studies have suggested that excessive iron intake can increase the risk of coronary heart disease and cancer. More recently, scientists have begun investigating the possible role of excess iron in the development and progression of diseases such as multiple sclerosis and arthritis.6
Preliminary research indicates that adequate iron is needed to help protect the nervous system and joints in these conditions, while abnormalities in iron metabolism may lead to an increase in oxidative damage and inflammation that damages tissues.9
Iron plays a key role in oxidative stress and photo-induced skin damage due to the generation of reactive oxygen species (ROS) by ultraviolet (UVA) and iron.7
Iron overload can lead to the formation of iron deposits in the skin and to complications of venous disease and hereditary hemochromatosis.7
Iron supplements can interact with several medications, including levodopa (used to treat restless leg syndrome and Parkinson’s disease) and levothyroxine (used to treat hypothyroidism, goiter, and thyroid cancer).
Anyone considering taking an iron supplement should first discuss this with their physician or health care practitioner as some of the signs of iron overload can look quite similar to those of iron deficiency. An excess of iron can be dangerous, and iron supplements are not recommended except in cases of diagnosed deficiency or where a person is at risk of developing iron deficiency.
Attempting to achieve optimal iron intake and status through dietary means is preferable in order to minimize the risk of iron overdose and ensure a good intake of other beneficial nutrients found alongside iron in foods.
Intravenous iron sucrose and oral iron therapy are the main therapies for iron deficiency anaemia (IDA), but there is still a debate regarding their efficacy and especially as to which one is the best choice during pregnancy.
A meta-analysis of randomised controlled trials comparing patients treated with intravenous iron sucrose (intravenous group) with those treated with oral iron (oral group) for IDA during pregnancy was performed. The primary outcomes of interest were mean maternal haemoglobin and serum ferritin levels at the end of treatment. Secondary outcomes were treatment-related adverse events and foetal birth weight.
Six randomised controlled trials, involving a total of 576 women, were included in the present review. Significant increases in haemoglobin [mean difference (MD), 0.85; 95% confidence interval (CI), 0.31-1.39; p = 0.002] and ferritin levels (MD, 63.32; 95% CI, 39.46-87.18; p < 0.00001) were observed in the intravenous group. Compared with the oral group, there were fewer adverse events in the intravenous group (risk ratio, 0.50; 95% CI, 0.34-0.73; p = 0.0003). There was no significant difference in birth weight between the two groups.
For pregnant women who could not tolerate the side effects of oral treatment or required a rapid replacement of iron stores, intravenous iron sucrose was associated with fewer adverse events and was more effective than regular oral iron therapy.