Professor, Dept. of Medicine,
Anemia is the most common of all blood disorders. Anemia results from reduced red blood cell production in the bone marrow. Nutritional anemia is defined as anaemia which occurs when there is a deficiency of one or more of the essential nutrients required for the synthesis of haemoglobin and the production of erythrocytes. Several nutrients are required for erythropoiesis. The World Health Organisation (WHO) defines anaemia as hemoglobin level <13 g/dL in men and <12 g/dL in women.
Iron, folic acid, vitamin B12, protein, pyridoxine, vitamin C, copper and possibly vitamin E are all necessary for the proper function of the bone marrow. Iron is an essential component of haemoglobin and a large proportion of nutritional anaemia in the world is caused by its deficiency. Iron deficiency tends to be most common when the intake is not enough to meet the demands of growth, e.g. in pregnancy, during infancy and at adolescence. Infections and parasitic infestations are also important; they may interfere with the activity of the marrow, or increase erythropoiesis by causing blood loss or haemolysis. Iron deficiency also occurs in malabsorption syndromes.
Anaemia (megaloblastic anaemia) due to deficiency of folic acid and vitamin B 12 is much less common. Both folic acid and B 12 Play a key role in cellular metabolism and are needed for the normal development of the erythrocytes in the bone marrow. Folic acid deficiency is more common than that of vitamin B 12, and is mostly seen during pregnancy, when the demands of the fetus are added to those of the other. Apart from pregnancy, deficiencies of folic acid and B 12 are rare except in Malabsorption and in certain diseases of the bowel as, for example, tropical sprue.
Anemia is a widespread public health problem associated with an increased risk of morbidity and mortality, especially in pregnant women and young children. It is a disease with multiple causes, both nutritional (vitamin and mineral deficiencies) and non-nutritional (infection) that frequently co-occur.
Prevalence of nutritional anaemia in ASIA
10 % adult males.
30-50 % adult females.
The rates are higher amongst pregnant women reaching 37 – 75 % in certain regions of India, Pakistan and Bangladesh. 50% children. The rates are higher in children under the age of 2 years.
Daily dietary requirement of iron
|Female (15 to 45 years)||2-3 mg|
|Maximum bioavailability from normal diet||4 mg|
|Dietary requirement for folate||Safe level of intake (μg/24h)|
|Children 1-6 years||50|
|Daily requirement of vitamin B12 Group||Safe level of intake (ug/24 h)|
|Children 1-10 years||0.04 ug/kg|
Symptoms of Nutritional anemia
Symptoms of anemia are usually very vague and hence, it goes undetected in many people. People tend to ignore these symptoms until they become quite disturbing.
- Rapid heart beats
- Shortness of breath
- Poor concentration
- Weak memory
- Easy bruising of body parts
- Slow healing of wounds
- Worsening of symptoms of other diseases
- Angina – heart pain from insufficient oxygen
- Claudication – cramped pains in muscles being used.
- Pica – the consumption of non-food items like wax, dirt, paper is often a symptom of anemia.
Vitamin B12 neuropathy
A minority of patients with vitamin B12 deficiency develop a neuropathy due to symmetrical damage to the peripheral nerves, and posterior and lateral columns of the spinal cord. The legs are usually more affected than the arms. Psychiatric abnormalities and visual disturbances may also occur.
Some of the most common causes of nutritional anemia are:
- Iron deficiency
- Vitamin B12 , Folic acid deficiencies (these usually occur together)
- Faecal blood losses due to intestinal parasites (Necator americanus , Ancylostoma duodenale Trichuris trichuria)
- Lead toxicities
- Infectious diseases like malaria
- Vitamin E and B6 deficiencies.
- Premature born infants.
- Medications which
- Prevent iron absorption from the gut e.g. ‘proton pump inhibitors’ in treating acidity, tetracycline etc.
- Cause chronic, mild bleeding from the gut e.g. NSAIDs (ibuprofen, naproxen used widely as pain-killers).
- Aspirin is another widely used medication known to cause mild to moderate bleeding from the gut.
- Hydrocortisones and valproic acid are drugs which cause folic acid deficiencies.
- Vitamin B12 deficiency can be caused by drugs like amoxicillin (antibiotic), and phenytoin (anti-convulsive).
Risk factors for nutritional anemia:
Ones chances of developing anemia increase particularly if they are:
- Menstruating and having heavy bleeding or excessively long periods (monthly blood loss depletes iron)
- Athletes (especially endurance athletes)
- An alcoholic
- Vegetarians or vegans
- Using nonprescription drugs and natural remedies whose side-effects are less known.
- Habituated to having tea in excess (tannin in tea causes decreased absorption of iron)
Diagnosis of Nutritional anemia:
Anemia is diagnosed through blood checkups and clinical examination.
A simple blood test called “complete blood count (CBC)” provides an idea of the hemoglobin count and type of anaemia. Other tests required of anemic patients are
- Blood Smear: study the structure of red blood cells with a microscope after preparing a slide smear.
- Serum iron, iron binding capacity and Serum ferritin: to detect iron deficiency.
- Reticulocyte count: Reticulocytes are immature red blood cells. Their raised levels in the blood indicate an increased destruction of red blood cells.
- Serum Vitamin B12 and folic acid: Measured to rule out their deficiencies.
- Bone marrow biopsy: any abnormalities in cells which produce the red blood cells can be identified by studying a sample of bone marrow.
Treatment for Nutritional anemia:
A balanced and nutritious diet can go a long way in reversing anemia.
- Red meats, egg yolks, clams & liver are some of the richest sources of iron
- Spinach and other dark leafy vegetables
- Dried beans
- Nuts, seeds
- Dried fruits (apricots, peaches, raisins, and prunes)
- Fortified cereals
- Fortified soy products
Cooking in iron pots and pans can also increase the amounts of iron consumed.
Vitamin C can enhance iron absorption in the body. So, a diet rich in vitamin C consisting of fresh fruits and vegetables (amla, guavas, limes, oranges, tomatoes, cabbages, etc.) should be maintained as well.
- Folic acid supplements
- Vitamin B12 injections
- Iron supplements
- Intake of iron supplements can cause toxicity in some persons. A rare genetic disorder called hemochromatosis causes increased absorption of iron leading to an overload. This condition is as dangerous as having too little iron in the body. Since men lose less iron compared to women, hemochromatosis is more prevalent in men.
In conclusion, nutritional anaemias are the second largest group of nutritional disorders after protein-energy malnutrition. The individual is most vulnerable at those periods of life when the requirements for nutrients are increased because of the demands of growth. In many parts of the tropics nutritional anaemia is particularly common on account of inadequate nutrition and super-added parasitic or helminthic infections which further increase the requirements of nutrients. The present improvement has been brought about by better standards of health care, especially during infancy and pregnancy, and better nutrition, together with public health measures.
- Mother and Child Nutrition in the Tropics and Subtropics Chapter 9 Nutritional Anaemia 339—350
- Harrison’s principle of internal medicine, 18 edition.
- Davidson’s principle and practice of medicine, 21st edition
- WHO scientific group, reports on nutritional anaemia