Anemia: B12 need or iron deficiency
Which one is it?
During my years in practice, I’ve seen one area that has consistently been confusing for patients and even for providers. Anemia.
Anemia occurs when your red blood cell count or your hemoglobin gets low and you can no longer deliver enough oxygen to cells to fuel them. The most common nutritional causes of anemia are iron deficiency and Vitamin B12 deficiency. Symptoms of anemia include:
Fatigue
Shortness of breath
Dizziness
Weakness
Pale skin
Brittle nails
Rapid heart rate
Cold hands & feet
Headaches
Irritability
Sore tongue or mouth sores
It’s important to know that anemia is a SYMPTOM, not a cause of disease and we must always look for a cause when anemia is present.
Next, let’s talk about some standard blood tests that look at anemia: red blood cells, hemoglobin, and hematocrit.
Next, let’s talk about some standard blood tests that look at anemia: red blood cells, hemoglobin, and hematocrit.
Red blood cell count is a standard test as part of a complete blood count (CBC). The normal range for red blood cells is, depending on which lab is being used (I got my ranges from LabCorp), is 3.8-5.3. When I interpret labs, I will often see patients display fatigue and other symptoms of anemia when their red blood cells drop below 4.2 for men and 4.0 for women. (When I say women, I mean menstruating females.)
Along with low red blood cell count, a person’s hematocrit (HCT) will often be low when anemia is present. HCT is also part of a CBC and it is a percentage of the volume of red blood cells in a known volume of blood. A ‘normal’ range is 34-46%, but if a man dips below 40% and a woman dips below 37%, symptoms of anemia may be present and need to be investigated.
Finally, hemoglobin (HGB) can be decreased with anemia. Hemoglobin is the molecule that carries oxygen within a red blood cell and it’s also a standard part of a complete blood count. A normal range is 11-16, but men may have symptoms of anemia below 14.0 and women may have symptoms when their levels are below 13.5.
I will often see symptoms of anemia despite ‘normal’ test results. Why? Conventional lab ranges will keep you out of the hospital, but they just aren’t designed to keep you in optimal health. The reason I see anemia symptoms when things are ‘normal' is because conventional lab ranges aren’t sensitive to the individual or designed to keep you optimally healthy.
Frequently, when anemia is recognized, a conventional provider will automatically prescribe iron. However, there is plenty of anemia caused by Vitamin B12 deficiency, too, and iron won’t help! Clearly, a little more investigation is needed to determine what nutrient the patient needs.
But how do we know which nutrient, or lack thereof, is causing the anemia? The lab measures I discuss below can help you decipher which nutrient, iron or Vitamin B12, may be causing anemia.
MCV. MCV stands for mean corpuscular volume. It is included with a complete blood count and when this value is low, it can indicate iron deficiency. When MCV is high, it can indicate Vitamin B12 deficiency.
MCH (mean corpuscular hemoglobin) is part of a CBC and, when low, indicates iron need. When MCH is high, it indicates B12 need.
MCHC. MCHC is part of a standard CBC and stands for mean corpuscular hemoglobin concentration. When MCHC is elevated, it can indicate a deficiency in B12 and when it is low, it can indicate iron deficiency.
Serum iron. This test is run when iron deficiency anemia is suspected and a low value indicates a deficiency in iron. This test might not be as useful to determine a nutritional cause of anemia if a person is taking an iron supplement.
Ferritin. Ferritin is the main storage form of iron and is a go-to test for me when it comes to iron deficiency anemia. When ferritin is low, it means that iron is needed.
Serum B12. Looking at B12 levels in the serum can be a way to look at a deficiency in Vitamin B12. However, serum B12 levels can be skewed and inaccurate, particularly if a person is taking a supplement that contains B12. I regularly see a conventional provider order serum B12 and not ask patients about supplements. They assume that the B12 levels are fine and then incorrectly rule it out as a cause of anemia.
Methylmalonic acid and homocysteine are more accurate ways to determine if there is a need for B12. Both of these tests will be elevated if there is a B12 need.
Your red blood cell count, MCV, MCH, and MCHC are standard as part of a Complete Blood Count and likely to be covered by insurance. A CBC is also a fairly inexpensive test. Serum iron, ferritin, serum B12, methylmalonic acid, and homocysteine are more advanced tests that are more expensive and, therefore, less likely to be covered by your insurance company unless your provider provides the proper diagnosis codes.
I do want to mention that anemia can be caused by other medical conditions, so if you are self-investigating anemia and can’t track down a cause, please see a medical provider. Also, iron loss in a person who isn’t menstruating (a man or a post-menopausal woman) can mean that there are more serious medical issues as well.
If covering topics like this more in-depth is interesting to you, I encourage you to join my email list. I will send emails about functional lab reference ranges, as well as have opportunities for you to dive in deeper and learn more about bloodwork. Having your labs run once a year (or more often if needed) is an important way to keep your finger on the pulse of your health.
I believe that our health, as a whole, will improve if we start to put medicine back into the hands of the people. Empowering people around their health and ensuring their medical autonomy is vital to a thriving community!
Disclaimer: Remember that this information is not medical advice. I’m A doctor, but I’m not YOUR doctor and I don’t know your medical history or any other details about your condition.