Where your DNA places you among other people, and the studies behind it.
Not tailored to your result, and not medical advice
Pair Iron With Vitamin C: Hemoglobin synthesis depends on iron, and the two dietary forms behave very differently. In this review, heme iron from meat, fish and poultry was absorbed at roughly 20 to 30 percent, while the non-heme iron in beans, lentils, tofu, spinach and fortified grains was absorbed at roughly 1 to 10 percent. Ascorbic acid had the most pronounced enhancing effect on non-heme iron, reducing ferric iron to the more absorbable ferrous form and holding it in a soluble chelate, and a small amount added to a rice meal roughly doubled absorption. Eating peppers, citrus, tomatoes or berries alongside plant iron sources is the practical version of that finding. Journal of Nutrition and Metabolism (PMC)
Drink Tea Between Meals: Polyphenols and tannins bind non-heme iron in the gut and block its uptake. In the trials summarised by this review, polyphenol-rich tea taken with iron-fortified wheat bread cut iron absorption by 56 to 72 percent, and phytates from bran and legumes inhibited absorption in a dose-dependent way. Calcium showed a similar effect, lowering absorption from a single meal from 10.2 to 4.8 percent. Tea, coffee, red wine and cocoa are all listed there as polyphenol sources, and the practical reading is timing rather than abstinence: move them and large dairy servings away from your main iron-containing meals. ACS Omega (PMC)
Quit or Avoid Smoking: Carbon monoxide from tobacco smoke occupies hemoglobin, and the body compensates by making more red cells, so smokers carry higher hemoglobin than non-smokers at the same iron status. In this analysis smokers averaged 3.3 g/L higher hemoglobin, rising with intensity to roughly 7 g/L above non-smokers among people smoking more than 20 cigarettes a day, and the authors found the smoking effect adds to the increase seen at high altitude. The consequence is that real iron deficiency in a smoker can sit hidden inside a normal-looking hemoglobin number. Stopping removes both that distortion and the far larger cardiovascular and cancer risks. Annals of the New York Academy of Sciences (PMC)
Account for Ongoing Blood Loss: In premenopausal women, recurring blood loss usually outweighs diet as an influence on hemoglobin. In a study of 473 premenopausal blood donors, menstrual blood loss was an independent determinant of both hemoglobin and ferritin and accounted for most of the explained variance in hemoglobin, around 8 percent, while time since the last whole blood donation was the leading determinant of ferritin. Women scoring in the heavy-bleeding range, 13 percent of that cohort, had about three and a half times the odds of anemia. Periods heavy enough to soak through protection within a couple of hours or to pass large clots are worth raising with a clinician rather than accepted as normal. Acta Obstetricia et Gynecologica Scandinavica (PMC)
Get Unexplained Low Hemoglobin Investigated: This is the honest limit of a lifestyle card: most reasons hemoglobin runs low are not behavioral. NHLBI lists blood loss including gastrointestinal bleeding, shortfalls of iron, vitamin B12 or folate, chronic kidney disease, inflammation from infection, cancer or autoimmune disease, and inherited forms of anemia that run in families. Diet reaches only one item on that list, so eating differently is not a substitute for finding out why a number is low. What a low result means in your case is a conversation for a clinician rather than something to correct on your own. NHLBI
How much of this is genetic?
Genetics explains 40% of why people differ in this trait. The rest is environment, daily habits and chance.
Heritability estimate: Adult twin/family estimates for hemoglobin concentration (Sala et al., Haematologica 2008: 0.34-0.42)
Background and further reading
Hemoglobin is the iron-containing protein inside red blood cells that binds oxygen in the lungs and carries it to tissues throughout the body. Hemoglobin concentration - the amount of hemoglobin per volume of blood - is one of the most commonly measured values on a routine complete blood count, and it reflects the blood's oxygen-carrying capacity. Typical adult reference ranges run roughly 13.5-17.5 g/dL in men and 12.0-15.5 g/dL in women, with values shaped by age, sex, altitude, and overall health. This polygenic score reflects the genetic tendency toward a higher or lower baseline hemoglobin concentration; it is not a measurement of your actual blood level, which comes from a blood test.
Genetic Basis: Baseline hemoglobin concentration is a heritable, highly polygenic trait. Twin and family studies in broad adult populations place the genetic contribution to normal variation at roughly 34-42%, with higher figures reported in younger samples [3]. Large genome-wide association studies of blood-cell traits, including work from the UK Biobank and the Blood Cell Consortium, have identified thousands of variants at hundreds of loci influencing red-cell measures [1][2]. Signals cluster in genes governing red-cell production and hemoglobin biology, such as the beta- and alpha-globin gene clusters (HBB, HBA1/HBA2), the HBS1L-MYB region that helps set fetal-hemoglobin and red-cell output, TMPRSS6 and HFE which regulate iron availability, and PIEZO1, ANK1, and SPTA1 which affect red-cell membrane properties and survival. A polygenic score sums many such common variants of individually small effect.
Other Factors: Genetics sets a baseline, but hemoglobin concentration is strongly modulated by everyday and physiological factors. Iron, vitamin B12, and folate status are major inputs, since these nutrients are required to build hemoglobin and red cells. Living at high altitude, smoking, and dehydration tend to raise measured concentration, while pregnancy, recent blood donation, menstrual blood loss, and hydration can lower it. Kidney function matters too, because the kidneys produce erythropoietin, the hormone that drives red-cell production. Because of these influences, a single measured value reflects far more than genetics alone, and an actual reading comes from a blood test rather than from this genetic score.
The published research behind your score, and the variants it draws on.
24 published scores from 10 studies
The hemoglobin score combines 24 polygenic scores drawn from 10 published studies.
Vuckovic D, et al. The Polygenic and Monogenic Basis of Blood Traits and Diseases. Cell (2020)
These traits are influenced by some of the same genes and variants as this one
RBC Count: The number of red cells per unit of blood, a measure of oxygen-carrying capacity.
WBC Count: The number of immune cells circulating in your blood.
HbA1c: Glycated hemoglobin, reflecting average blood sugar levels over the past 2-3 months.
Content updated August 2026.
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