Why Women Don't Get Enough Iron - And what's the impact?

Iron deficiency is the world's most common nutritional deficiency, and women are disproportionately affected. The reasons go beyond diet alone. The gap between how much iron women need and how much they actually absorb is shaped by three factors that most women are never told about: the physiological demands of the menstrual cycle, the fundamental difference in how the body processes heme versus non-heme iron, and the way gut health affects iron absorption even from a nutritionally adequate diet. You can eat iron-rich foods consistently and still run low.

The menstrual cycle creates a monthly iron deficit

The most common cause of iron deficiency in premenopausal women is menstrual blood loss. The NIH Office of Dietary Supplements notes that the recommended daily intake of iron for women aged 19 to 50 is 18 mg per day, more than double the 8 mg recommended for adult men. This gap exists specifically because of menstrual losses. Women with heavier cycles lose proportionally more iron each month and may need even higher intake to maintain adequate stores.

The challenge is that this monthly loss is not always visible in the way women expect. A period does not have to be dramatically heavy to create a meaningful monthly deficit. Moderate bleeding over five to seven days, repeated every month for decades, creates a steady draw on iron stores that dietary intake often does not fully replace.

For women in perimenopause, the picture can be more complicated. Cycles that become heavier or more irregular in the years before menopause can accelerate iron depletion at a time when most women are not thinking about iron at all.

"There has to be some correlation with how women are treated as young women versus how they enter into perimenopause and menopause later."

— Dr. Samantha Ess, ND, Naturopathic Doctor specializing in hormone health and fertility

Heme versus non-heme iron: the absorption gap women are rarely told about

Not all dietary iron is equivalent. The NIH StatPearls review on dietary iron documents that heme iron, found in animal foods including red meat, organ meats, poultry, and seafood, is absorbed at approximately 25 percent efficiency. Non-heme iron, found in plant foods, fortified grains, and most iron supplements, is absorbed at 17 percent or less, and can drop to as low as 2 to 3 percent in the presence of dietary inhibitors.

The inhibitors that block non-heme iron absorption are present in many foods women eat daily as part of an otherwise healthy diet: phytates in whole grains and legumes, polyphenols in coffee and tea, and calcium in dairy products all reduce non-heme iron uptake. A woman who drinks tea or coffee with meals, eats a primarily plant-based diet, and relies on fortified cereals for iron may be consuming what looks like adequate iron on paper while actually absorbing only a fraction of it.

Heme iron absorbed through its dedicated uptake pathway is largely unaffected by these inhibitors. This is why the whole-food source matters as much as the total milligrams on a nutrition label.

Gut health creates a third layer of the problem

Iron absorption happens in the small intestine, and the integrity and function of the gut lining directly affects how much iron moves from the digestive tract into the bloodstream. Women with any degree of intestinal inflammation, increased permeability, or gut microbiome disruption absorb less iron from the same dietary intake than women with healthy gut function. This means that gut health is an iron absorption variable, not just a digestive comfort issue.

The connection runs in both directions. Low iron affects gut cell turnover, because the rapidly dividing cells of the intestinal lining have high iron requirements. And gut dysfunction reduces iron absorption, which deepens the deficit. This cycle can make iron repletion harder to achieve through diet alone.

"The gut is 70% of the immune system."

— Dr. Samantha Ess, ND, Naturopathic Doctor specializing in hormone health and fertility

Why the standard advice to eat more spinach is incomplete

Spinach is widely cited as an iron-rich food. It does contain a meaningful amount of iron per serving. But spinach iron is non-heme iron, and spinach also contains oxalates that further inhibit its own iron absorption. The net iron delivery from a serving of spinach is considerably lower than the label would suggest. The same is true of lentils, fortified cereals, and most other plant-based iron sources when consumed in typical meal contexts with coffee, tea, or other inhibitors present.

This does not mean plant foods are not valuable. It means that understanding the absorption reality is necessary to close the gap, and for many women, whole-food animal sources of iron are the most reliable path to adequate absorption.

What bioavailable iron actually looks like

Organ meats, particularly grass-fed bovine liver, are among the most concentrated sources of heme iron in the human diet. Liver has been used across cultures for centuries as a targeted nutritional intervention for women during pregnancy and postpartum, precisely because of its iron density and bioavailability. It also provides naturally occurring B12, CoQ10, vitamin A as retinol, and zinc, the cofactors the body uses alongside iron for energy production and cellular function.†

Beef Organ Complex, a whole-food blend of grass-fed liver, heart, kidney, and female-focused organ powders, delivers this whole-food iron alongside the broader nutrient matrix that supports how the body uses it.† Pink Stork Beef Organ Complex is the first in its category to earn the Clean Label Project Purity Award, tested for more than 400 environmental and industrial contaminants at ISO-accredited third-party laboratories. It is formulated with input from an expert advisory panel of OB/GYNs and registered dietitians.

For women who want to understand the full picture on iron absorption and form, see our guide on heme iron versus non-heme iron for women and our guide on iron deficiency and hair loss.

"Don't just buy just to consume because you saw it somewhere. Truly figure out what it is specifically that you're battling, what it is that you need, what your lab work is saying, and then fill in the gaps from there."

— Dominique Landry, Founder of Fit Enough

Frequently asked questions

How common is iron deficiency in women?

Iron deficiency is the world's most common nutritional deficiency. The NIH StatPearls review notes that prevalence in adolescent girls and women of reproductive age is between 9 and 11 percent when anemia is used as the threshold, but rates of low ferritin without anemia are considerably higher, with some research suggesting more than 20 percent of women of childbearing age are affected.

Can you be iron deficient and eat meat regularly?

Yes. Menstrual blood loss is the dominant driver of iron deficiency in premenopausal women, and monthly losses can exceed what diet replaces regardless of meat consumption, particularly with heavier cycles. Gut absorption barriers can further reduce the effective delivery of dietary iron.

Why does coffee affect iron absorption?

Coffee contains polyphenols that bind to non-heme iron in the digestive tract and inhibit its absorption through the intestinal wall. Consuming coffee within an hour of an iron-rich meal can meaningfully reduce the amount of non-heme iron absorbed. Heme iron from animal sources is less affected by this inhibition.

Is spinach a good source of iron for women?

Spinach contains iron, but it is non-heme iron and its absorption is further inhibited by oxalates in the spinach itself. The net iron delivery from spinach is lower than the total iron content on a nutrition label suggests. It is a useful dietary component but should not be the primary strategy for iron repletion in women with low ferritin.

What is the best form of iron supplement for women?

Heme iron from whole-food sources is the most bioavailable form. For women who want to supplement, whole-food organ meat supplements providing naturally occurring heme iron are a gentler option than high-dose synthetic iron supplements, which commonly cause gastrointestinal side effects at therapeutic doses.†

Do perimenopausal women need to worry about iron?

Yes. Women whose cycles become heavier or more irregular during perimenopause can experience increased monthly iron losses at a time when iron is not top of mind. Ferritin testing is as relevant for perimenopausal women as it is for younger women with heavy periods.

Does gut health affect iron absorption?

Yes. Iron absorption occurs in the small intestine, and gut lining integrity and microbiome health directly affect how much iron moves into the bloodstream from dietary sources. Women with any degree of gut inflammation or permeability may absorb less iron from the same dietary intake than women with healthy gut function.†

† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Always consult your healthcare provider before starting any new supplement, especially during pregnancy, breastfeeding, or while managing a medical condition. Keep out of reach of children.