Sunday, September 24, 2023

Supplements for anemia

Supplementation for nutrient-deficiency anemias involves correcting nutrients such as iron, vitamins B9 and B12, protein, and omega-3 oils.

Executive Summary
Here are the supplements that are advisable for managing nutrient-deficiency anemias.

Necessary, based on the type of anemia:
Iron (100 mg twice a day of elemental iron);
B-vitamin Complex (must have vitamins B9 and B12);
Protein (10 to 20 g a day extra); and
Omega-3 fish oils (1,000 mg a day).

Read the article for more details.

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Many people think anemia means a shortfall of iron in the body. But actually, it is the lack of enough red blood cells in your blood. In fact, more specifically, it is the reduced ability of the blood to carry oxygen to the body tissues.

Unlike many medical conditions, anemias are caused in diverse ways. Some of the causes, such as cancers and congenital problems, cannot be addressed by supplements. However, nearly a third of anemias are caused by nutrient deficiencies. In this article, I will cover such nutrient-deficiency anemias, how they develop, and the supplementation strategy for each of them.


Our blood has red blood cells (RBC) that carry oxygen from the lungs to cells of the body and then carry carbon dioxide back to the lungs to be exhaled. These cells contain a protein called hemoglobin, which binds to oxygen or carbon dioxide as the need may be.

Hemoglobin is made up of iron and has red colour. It is nearly one-third by weight of the blood and its colour makes our blood red. Hemoglobin is also responsible for the shape of RBCs. Normal RBCs are round in shape with depressed centers—a sort of a doughnut without a hole in the middle.

Signs and Symptoms of Anemias

Here is my detailed video about the signs and symptoms of anemia. If you prefer to read, you can check many links given in this article later.

Causes of Anemias

Since anemias are caused by the reduced ability of the blood to carry oxygen around, they can be caused in multiple ways:

  • Reduced production of hemoglobin, due to low iron intake;
  • Reduced production of hemoglobin, due to low absorption of iron in the body;
  • Normal production of hemoglobin but improper functioning of hemoglobin;
  • Less production of RBCs;
  • More destruction of RBCs in the body;
  • Loss of RBCs due to blood loss; and
  • Dilution of blood due to excess fluid consumption.

As mentioned earlier, some of these are due to genetic factors or serious medical causes. So we will restrict our discussion only to those anemias caused by nutritional deficiencies. There are three of them:

Iron-Deficiency Anemias (IDA)

These are caused by, well, iron deficiency in the body. The deficiency could arise due to three broad reasons:

  1. Deficiency of iron in the diet;
  2. Less iron absorption in the intestines due to inflammatory diseases such as inflammatory bowel disease; and
  3. Loss of blood due to an accident, menstruation, internal bleeding, or even excess blood donation.

These anemias are common in pregnancy. The solution is to increase iron intake. Read more: Understanding Iron Supplements for Anemia.

Just for your information: Iron is stored in the body in the form of a protein called ferritin. It is transported around the body by a different protein called transferrin. So to know the iron levels in your body, you don’t check hemoglobin; you check ferritin and transferrin. But leave those decisions to your doctor.

How Iron Deficiency Anemias Develop

Iron-deficiency anemia develops in three stages:

  1. Reduction in iron stored in the body but no reduction in RBCs or hemoglobin—no anemia. One may notice some fatigue and the ability to do heavy exercises reduces;
  2. Major reduction in iron stores; hemoglobin is reduced but the shape of RBCs is unchanged;
  3. Iron-deficiency anemia (almost no iron stores in the body; low hemoglobin; less number of RBCs and smaller size of RBCs).

Read more: What Are the 3 Stages of Iron Deficiency?

Now, don’t try to become a ‘doctor’ but from the above description, you would be able to guess that one should first test for Complete Blood Count (CBC). If the RBC and hemoglobin numbers are abnormal, one should then check ferritin and transferrin (called Total Iron Binding Capacity or TIBC).

TIBC indicates the spare capacity to carry iron. If TIBC is high, it means that there is not much iron available to be transported. Thus, low ferritin and high TIBC would tell that you have iron deficiency. But once again, leave that diagnosis to your doctor.

Megaloblastic Anemias

Megalo– means large and blasts are immature cells. So megaloblasts are large, abnormal-shaped, and immature RBCs.

These are caused by a deficiency of two vitamins: vitamin B9 (folic acid) and vitamin B12 (cobalamin). These two vitamins are needed for the synthesis of cell DNA. Without them, cells become damaged and dysfunctional.

The deficiency of vitamins B9 and B12 could be due to three broad reasons:

  1. Deficiency of them in the diet;
  2. Problems with their absorption in the intestines; and
  3. Problems with their utilisation in the body.

Read more: Megaloblastic Anemia.

These anemias are common in old age. Normally, stomach acid helps vitamin B12 from the food to be released. But with age, our bodies produce less stomach acid. So older people find it difficult to get adequate vitamin B12, even if their food has enough amount of it.

Alcohol consumption reduces vitamin B9 absorption.

Pernicious Anemia

A specific type of anemia called Pernicious anemia develops when the body cannot absorb or utilise vitamin B12. Normally, our stomach makes a protein called intrinsic factor (IF), which binds to vitamin B12 so that it is absorbed in the intestines. But when the stomach lining is weakened, not enough IF is produced. This leads to vitamin B12 deficiency and anemia. This typically affects after the age of 30 years. Read here: Pernicious anemia.

The solution for these anemias is to increase the intake of vitamins B9 and B12.

Protein-Deficiency Anemia

Insufficient protein intake reduces the body’s metabolism. That decreases the production of a hormone called erythropoietin (EPO) made by the kidneys. This, in turn, reduces the RBC production.

You must be knowing that professional athletes do hard workouts. The idea is to push up their bodies’ oxygen demand, which increases their basal metabolic rates (BMR). That, in turn, increases the production of RBCs. This is an adaptive process that works in reverse in case of low protein intakes.

This anemia is seen in people with low protein intakes, such as vegans and the elderly. Read here: Protein-deficiency anemia.

The solution for protein-deficiency anemia is obviously to increase protein intake.


It is difficult to know which anemia you have without taking the help of a medical doctor. So do not try to treat your anemia yourself. Always seek medical help. This article is written to give you a better understanding of your anemia and your options. Most of the supplements useful for anemia are basic healthy nutrients such as iron, vitamins, proteins, and omega-3 oils. They help many systems in the body and so taking them is not harmful, if you suspect you have anemia. However, doing that without taking any medical advice is not a proper strategy.

Supplementation Strategies for Anemias

If anemia is due to a specific nutrient deficiency, supplementation will help:


Supplemental iron comes in two forms: heme and non-heme.

Heme iron comes from animal sources. It is made up of hemoglobin and myoglobin. Both of them are well-absorbed in the body (15-35% of the iron is absorbed).

Non-heme iron comes from plant sources, such as vegetables and beans. Plant substances such as tannins and phytates can reduce the absorption of non-heme iron. Similarly, calcium and dietary fiber can reduce the absorption of non-heme iron. On the other hand, vitamin C improves the absorption of non-heme iron by converting it into a form that is easily absorbed by the body. That is why one is advised not to drink tea or milk, or take a calcium supplement when taking iron supplements. One is also advised to simultaneously take vitamin C with such a supplement. Typically, 2-20% of the non-heme iron is absorbed in the body.

Iron supplements may contain various salts of iron such as ferrous sulphate, ferrous gluconate, ferrous fumarate, or ferrous bisglycinate. Since different weights of these salts give the same amount of iron, the norm is to specify something called Elemental Iron, which is the amount of iron that the supplement contains (obviously, only a part of it will be absorbed in your body).

Normally, you need about 18 mg a day of iron absorbed from food. If you have iron deficiency, you can take an additional 10 mg a day from supplements. Now comes the tough part:

Depending on the salt used (sulphate, gluconate, bisglycinate, etc), the absorption of elemental iron changes. For example, bisglycinate has 2.5 times the absorption of sulphate. So you would need 2.5 times more elemental iron in a ferrous sulphate supplement than a ferrous bisglycinate supplement to get the same amount of iron into your body.

In other words, if you take ferrous sulphate which has 10% absorption, you need 100 mg of ferrous sulphate (the correct wording is: 100 mg of elemental iron in the form of ferrous sulphate) a day. On the other hand, if you take ferrous bisglycinate which has 15% absorption, you would need 65 mg of it a day.

Remember that ferrous sulphate has more side effects such as constipation or diarrhea. But it is cheaper than fumarate or bisglycinate varieties. So one has to judge all these factors. Are you having fun yet? Read here: Ferrous sulfate: 7 things you should know.

Vitamin C

Vitamin C helps in the absorption of iron. A small amount of vitamin C should be taken with non-heme iron for better absorption (vitamin C does not change the absorption of heme iron). Vitamin C by itself has no role in correcting any anemia.

Vitamin B9

Take 500 µg a day till the deficiency is covered. Give three to six months to see results.

Some experts even suggest 1,000 µg of vitamin B9 a day. But I feel it is a little too high because vitamin B9 masks a vitamin B12 deficiency. People who take vitamin B9 supplements in those quantities will show normal vitamin B12 levels in a blood test even if they are deficient in it. Read on Johns Hopkins Medicine: Folate Deficiency Anemia.

Vitamin B12

Vitamin B12 is found in animal products such as dairy, eggs, and meat. Since many vegetarians avoid dairy for heart health reasons, they may end up with vitamin B12 deficiency. Vegans will definitely have vitamin B12 deficiency.

Many doctors give 1,000 µg of vitamin B12 injection once a week. However, 1,000 µg a day of vitamin B12 supplement to be taken orally is equally effective, if there is no issue with vitamin B12 absorption in the body.

I have personally seen excellent results with much lower vitamin B12 levels as long as the supplement is from a good natural source (so that its absorption is high in the body). Keep in mind that your daily requirement of vitamin B12 is just 2.4 µg under normal conditions. If you take more than this, the excess just passes through the urine. So I feel there is no great benefit in taking very high doses of vitamin B12 such as 1,000 µg a day.

Read on Cedars-Sinai: Vitamin B-12 Deficiency Anemia.


Aim for 10 to 20 g of high-quality protein such as whey or soy protein. Look for a complete protein containing Protein-Digestibility Corrected Amino Acid Score or (PDCAAC) of 1.

Omega-3 Oils

If the anemias are of certain types called aplastic, hemolytic, or inflammatory kind, autoimmune conditions may prevail. In such cases, an autoimmune protocol (AIP) diet may be helpful.

In such situations, intestinal inflammation will be high. Omega-3 oils are anti-inflammatory and will help. Fish oils or algal oils are the best sources of omega-3s. Aim for 1,000 to 2,000 mg of DHA and EPA together a day. For in-depth coverage, read on this website: Omega–3 oils: A complete guide.

Long-Term Complications

If untreated, anemias can have serious long-term complications:

  • Chronic and extreme fatigue;
  • Pregnancy complications, such as premature birth;
  • Fast or irregular heartbeat (arrhythmias);
  • Heart enlargement or failure: The heart pumps more blood to cover up for lower oxygen supply by the blood;
  • Death.

To Read More

  1. Harvard T.H. Chan School of Public Health: Iron
  2. Winchester Hospital: Anemia: How Food and Vitamins Can Help
  3. WebMD: Dietary Iron and Iron Supplements
  4. Cleveland Clinic: Oral Iron Supplementation
  5. MedicalNewsToday: What is nutritional deficiency anemia?
  6. National Library of Medicine: Megaloblastic Anemia
  7. NHS, UK: B Vitamins and Folic Acid

Articles in Nutrients Series

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  3. Vitamin A: A Complete Guide
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  5. Turmeric (Curcumin): A Complete Guide
  6. Lutein: A Complete Guide

Articles in Supplementation Series

  1. Why Do We Need Supplements?
  2. Supplements for Various Age Groups
  3. Supplements for Preventing Ageing & Age-Related Diseases
  4. Supplements for Type 2 Diabetes
  5. Supplements for Osteoarthritis
  6. Supplements for Hair Loss
  7. Supplements for Fatty Liver
  8. Supplements for Autoimmune Disorders
  9. Supplements for Anemia
  10. Supplements for Prostate Enlargement
  11. Supplements for Macular Degeneration
  12. Supplements for PCOS
  13. Supplements for Parkinson’s Disease
  14. Supplements for Gout
  15. Supplements for Eczema

Articles in Supplementation Series

  1. Why Do We Need Supplements?
  2. Supplements for Various Age Groups
  3. Supplements for Preventing Ageing & Age-Related Diseases
  4. Supplements for Type 2 Diabetes
  5. Supplements for Osteoarthritis
  6. Supplements for Hair Loss
  7. Supplements for Fatty Liver
  8. Supplements for Autoimmune Disorders
  9. Supplements for Anemia
  10. Supplements for Prostate Enlargement
  11. Supplements for Macular Degeneration
  12. Supplements for PCOS
  13. Supplements for Parkinson’s Disease
  14. Supplements for Gout
  15. Supplements for Eczema

First published on: 24th April 2022
Image credit: Blood flow photo created by kjpargeter –
Last updated on: 2nd June 2022


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