Many of us have heard the advice to use a multivitamin supplement with iron to ensure good health. Older individuals, in particular, grew up in an era in which the sadly portrayed results of “iron-poor, tired blood” which was advertised to millions of television viewers (and targeted to a geriatric audience).
Should all multivitamins contain iron?
In modern times, many people strive to obtain all the nutrients they need from food alone. Unfortunately, we know that is very challenging to achieve due to soil conditions and other factors.
However, it may be possible for iron, at least for some people. Nevertheless, many infants, children, teenagers, and women during their reproductive years fail to obtain the iron they need, and for these people or others diagnosed with iron deficiency anemia, an iron supplement is essential.
While the Recommended Daily Allowances for most nutrients are woefully inadequate, for iron, they may be reasonable. A Western diet that is high in meat, which is a rich source of iron, especially combined with iron supplementation, can frequently elevate iron stores to levels beyond that which is needed.
Iron deficiencyIron deficiency anemia can often go undetected without blood testing. Signs include fatigue, weakness, shortness of breath, poor circulation, rapid heartbeat and more. According to the World Health Organization’s definition of anemia (hemoglobin level of less than 13 g/dL in men and less than 12 g/dL in women), its presence more than doubles the risk of premature mortality, however, excessively high hemoglobin levels have also been associated with increased premature mortality.1
A study of long-term care facility patients found a 63% higher risk of mortality from any cause among those whose iron deficiency was mild and a 96% higher risk among those with severe deficiency over a five-year period.2 In a study of 17,030 subjects aged 66 years and older, anemia was associated with a greater than four-fold increase in the risk of death over three years of follow up, however, once more, when hemoglobin levels became high, an increase in death from any cause became evident.3
Numerous other studies exist that document an association between iron deficiency or anemia and mortality in different populations.
What are some of the consequences of too much iron?Iron is, by mass, the most common element on Earth. The mineral is needed for the formation of hemoglobin, the oxygen-carrying protein in red blood cells, and is, therefore, essential to human and other animal life. It’s also needed by the muscles and organs of the body. However, iron generates free radicals—byproducts of metabolism that can damage the body’s tissues, resulting in premature aging.
In the hereditary disease known as hemochromatosis, elevated iron levels result in deposits of the mineral in skin, glands, pancreas, heart and liver. Too much iron in the pancreas can dangerously lower insulin production, leading to elevated glucose levels. In the heart, iron deposits can lead to cardiac arrhythmias and heart failure. In the liver, it can cause cirrhosis and increase the risk of liver cancer.
While most people don’t have hemochromatosis, many get more iron than they need. Iron has been linked to increased risk or complications of numerous diseases.
Higher iron levels have been linked with diabetes. Diabetic women in one study were found to have serum ferritin levels that were three times greater than those of a control group.4 A review of epidemiologic studies examining the associations between iron and cardiovascular disease and diabetes concluded that the evidence was strong in support of the association between iron status and an increased risk of either disease.5
In human liver cells exposed to iron overload, significant inflammation occurred via nuclear factor-kappa beta (NF-kB) signaling.6
Cancer cells use iron to proliferate, and the cells’ uptake of the mineral can result in anemia in those afflicted with the disease.7 Oxidative stress generated by iron accumulation activates signaling pathways needed for tumor growth and induces epigenetic changes associated with metastasis.
Higher brain iron levels are associated with an increase in neurodegenerative diseases, including Huntington’s, Parkinson’s and Alzheimer’s disease, compared to the brains of healthy men and women.7 According to an article published in 2016 in Brain, “Iron accumulation is a cardinal feature of degenerating regions in the Parkinson's disease brain. As a potent pro-oxidant, redox-active iron may be a key player in upstream mechanisms that precipitate cell death in this disorder. Although an elevation in brain iron levels is a normal feature of ageing, the increase is greater in Parkinson's disease […] neurodegeneration in the affected regions may result from the potent redox couple formed by iron and dopamine itself […]”8
HypothesesThe most recent review concerning iron-mediated toxicity observed that the poor solubility of iron renders it a valuable commodity and that humans have evolved mechanisms to absorb, recycle and store iron while minimizing toxicity.9 The authors assert that “existing regulatory processes are more than adequate to limit the toxicity of iron even in response to iron overload. Only under pathological or artificially harsh situations of exposure to excess iron does it become problematic.”
However, in 2016, an article in Liver International noted that “Excess iron in the blood, in the absence of increased erythropoietic [red blood cell-producing] needs, can saturate the buffering capacity of serum transferrin and result in non-transferrin-bound highly reactive forms of iron that can cause damage, as well as promote fibrogenesis and carcinogenesis in the parenchymatous organs.”10
The Bottom LineHow does one know if one needs to supplement with iron? Routine blood work that includes serum ferritin and hemoglobin levels can provide the information your physician needs to diagnose iron deficiency anemia. Only those who are truly deficient should supplement with iron. Iron protein succinylate is a good choice if supplementation is necessary due to its superior absorption and decreased likeliness of gastrointestinal irritation.
- Martinsson A et al. Eur J Epidemiol. 2014 Jul;29(7):489-98.
- Hsu HS et al. Nutrition. 2013 May;29(5):737-43. 2013 May;29(5):737-43.
- Culleton BF et al. Blood. 2006 May 15;107(10):3841-6.
- Skalnaya MG et al. J Trace Elem Med Biol. 2016 Nov 16.
- Basuli D et al. Front Pharmacol. 2014 May 20;5:117.
- Li X et al. Molecules. 2016 Mar 17;21(3):322.
- Gozzelino R et al. Int J Mol Sci. 2016 Jan 20;17(1).
- Hare DJ et al. Brain. 2016 Apr;139(Pt 4):1026-35.
- Eid R et al. Biochim Biophys Acta. 2016 Dec 6;1864(2):399-430.
- Pietrangelo A. Liver Int. 2016 Jan;36 Suppl 1:116-23.
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