I hear from my patients all the time “Doc, I have been to 5 other doctors and no one can figure out why I get short of breath so quickly when I do any exercise. Why am I losing my hair, why do I have brain fog and why am I always tired? I have seen specialist after specialist and they say everything is okay all my labs are within the normal range”. So, when I see them the first thing I look at is the CBC blood test and in that test there is the MCV which is the mean corpuscular volume. This shows the size of the red blood cells. The range is 80-100 so if your MCV is 80-89 your red blood cells are a little smaller and that means you don’t hold onto oxygen as well. Which can mean you probably have an iron deficiency (ferritin). Each ferritin unit holds onto oxygen. So, even if your ferritin levels are within the range of 15-248 your ability to hold oxygen on a red blood cell is diminished. I found that anything under 45 could mean you actually are hypoxemia or low in oxygen in your blood which is why the symptoms we talked about at the beginning of the article start to manifest themselves.
When you have low ferritin you usually have low iron levels. The skin gets pale, and the oxygen levels in your organs decrease. This puts a strain on all your organs. The pulse oxygen monitor may say your oxygen is 95-99% but your organs are running low on oxygen. With low oxygen muscles become fatigued easily and the muscle can be damaged. Once they are damaged they repair slowly because oxygen levels are so low. You will tend to experience increased muscle pain, increased blood pressure, increased pulse rate as your heart works harder to push blood faster to get back to the lungs and get more oxygen but if you have low ferritin you won’t be able to hold on to oxygen and the vicious cycle just gets worse and worse.
With low ferritin you see more irregular heartbeats. The conditions related to low ferritin causing hypoxemia are restless leg syndrome, celiac disease, irritable bowel, depression, anxiety, hair loss, hypothyroid, ADHD, headaches, irregular mensuration, loss of libido. A number of studies have shown fixing low ferritin improves cognition. Next time someone says your numbers are all within the range you might want to look again at some of these labs. The treatment is to put a patient on oral iron which for most people I find it doesn’t work because they get upset stomach unless the iron tabs have vitamin C which decreases the side effects that iron can cause. But, if you are taking oral iron for low ferritin it will take 6-12 months in most people to correct it. Unless you are offered ferritin as an IV then you can correct it immediately.