Are Genes Shaping Blood Iron Levels in Women?

iron levels

Different groups show different rates of iron deficiency. A recent study investigated the genetic factors linked to iron levels for women.

Iron is an important mineral that helps blood cells carry oxygen to the body’s organs. Maintaining adequate levels of iron is vital to maintaining health. Different ethnic groups in the United States have documented differences in iron status. In particular, African American men and post-menopausal women have lower hemoglobin but higher serum levels of iron (iron stores) than others. Pregnant African American women also have higher rates of iron deficiency than white women, as do women from most non-white groups. The causes for these differences in the iron levels in women are not well understood.

In the American Journal of Clinical Nutrition, Gordeuk and Brannon present a summary of recent findings on the genetic factors influencing iron status in women. Understanding these genetic factors is important to understanding the mechanisms that lead to iron deficiency. They used the results from the Hemochromatosis and Iron Overload Screening Study, or HEIRS, which included 101,168 individuals over 25 years of age. These individuals were genotyped—that is, their DNA was sequenced. Gordeuk and Brannon then used information from a genome-wide association study to investigate the links between certain gene variants and iron levels in different groups.

Pregnant women typically had more frequent iron deficiency than non-pregnant women. This was highest in Hispanic women and lowest in Asian American women. Individuals with the C282Y mutation in the HFE gene, which has been linked to iron levels, had a decreased prevalence of iron deficiency. African American women had the highest level of iron stores than other groups, and higher levels were again linked to the HFE C282Y mutation. The more copies of the mutant allele an individual had, the lower the probability of iron deficiency and the higher the levels of iron stores.

Although there are differences between groups in the levels of iron deficiency and iron stores, part of this may be due to dietary factors and the use of iron supplements. This may be particularly true of Americans compared to people of other regions. Increased levels of iron stores may be linked to certain kinds of cancer or an increased risk of diabetes. Clinicians should exert care to ensure proper iron levels in pregnant women, in particular.

Written by C.I. Villamil

Reference: Gordeuk and Brannon. 2017. AJCN. Ethnic and genetic factors of iron status in women of reproductive age.