Case Study: I am a 49-year-old woman who doesn’t smoke, is relatively healthy and who weighs about 150 pounds. I have had celiac disease since 2009 and hypothyroidism. I tend to run on the low end of normal with my ferritin levels. A recent reading was 37 ng/mL, but it’s been 11 to 34 over the years, with a recent iron reading of 87 ug/dL.
This concerns my neurologist, whom I see for severe restless leg syndrome. I currently take 140 mg daily of ferrous sulfate.
The ferritin level doesn’t seem to be a concern for my internal medicine doctor, though the neurologist wondered why he isn’t trying to figure out why my ferritin levels run on the low end of normal.
Do I pursue that further with the internal medicine doctor or ask the neurologist if there is more investigating that he would like to pursue?
This is a seemingly simple question: Why a low ferritin with a normal iron level?
Ferritin is a protein that reflects total iron stores, so a modestly low ferritin like yours means borderline overall body iron. You are taking a fairly low amount of iron, and it might not have adequately repleted your stores.
Celiac disease, unless a gluten-free diet is meticulously followed, usually leads to poor iron absorption, so that might explain why your body isn’t at full iron levels despite your taking supplementary iron. Iron levels go up quickly after supplementary iron or iron-rich foods, and vary during the day.
Your neurologist is quite correct that even mild iron deficiency, proven only by the low blood ferritin, can worsen restless leg syndrome.
However, there are some other possibilities that need to be mentioned. One is that hypothyroidism can cause a low ferritin level in absence of iron deficiency, and you should be sure your thyroid level is right in the middle of normal.
Also, I don’t know why you are iron deficient in the first place. While the celiac disease is one possibility, I always want to make sure a hidden source of blood loss has been looked for, and for a 49-year-old woman especially, that means a thorough evaluation of the GI tract, especially the colon. Polyps, colon cancer and inflammatory bowel disease sometimes can have minimal symptoms. All could cause blood loss that you might not notice.
I certainly would readdress this issue with your internist, or ask to see a gastroenterologist.
Dr. Keith Roach
Dr. Keith Roach graduated from the University of California, Berkeley, with a degree in molecular biology. He earned his M.D. at the University of Chicago, and did his internship and medicine residency training there.
In 2000, Dr. Roach moved to New York, joining the faculty at Weill Cornell Medical College and New York Presbyterian Hospital as an Associate Attending Physician and Associate Professor of Clinical Medicine. He has won every major teaching award offered by that institution. He also served as program director for the primary care internal medicine training program.
The focus of his research is in the prevention of disease with rational use of screening technology and with tools that empower people to make lifestyle choices that improve not only their health but their life expectancy. Dr. Roach also serves as Chief Medical Officer for Enforcer eCoaching, a company dedicated to giving individuals specific daily coaching on improving diet, smoking cessation, weight loss and exercise.
Dr. Roach lives in Larchmont, N.Y. with his wife, Dr. Victoria Muggia, M.D. (a specialist in infectious disease), and their three teenagers, David, Hannah and Jonathan. Dr. Roach is a competitive triathlete.
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