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How Women & Men Differ Nutritionally

By Edwina Clark, MS, RD

October 19, 2026

Women and men are different. Duh, you say. That includes our nutritional needs. Yet too often women and men eat and supplement the same way, especially female-male couples, of course.

But while both sexes have some of the same nutrient shortfalls, there are some key differences. In addition, women and men can face differing health challenges while also potentially pursuing different health goals. Pregnancy and menopause, for example, are phases in which women suddenly have very different nutritional needs. Meanwhile, some women may seek to be leaner while some men want to be more muscular.

Below, we explore 1) how women and men differ nutritionally, 2) where they share nutrient shortages (in both vitamins and minerals), and 3) which vitamins and minerals women come up short far more often than men.

The biggest nutritional differences between men and women

First, note that sex is only part of the equation. Age, body composition, exercise, dietary patterns and reproductive status all influence nutritional needs:

• As you get older, you will usually require fewer calories.

• Those individuals with more muscle mass and those who exercise more often will need more calories.

• Those who eat a plant-based diet will have different nutritional requirements than those who are eating a diet high in red meat, for example.

• Meanwhile, calorie intake and nutrient needs change during each phase of conception, pregnancy and lactation for women.

That being said, for the most part, men require more energy (calories), protein, fiber and other nutrients compared to women. Exceptions do exist, however, as you will see below.

1. Energy

Men generally require more calories than women because they tend to have larger bodies, more lean muscle mass and higher resting metabolic rates. Women typically have lower calorie needs, but their energy requirements can fluctuate during pregnancy, breastfeeding and different life stages.

Meanwhile, physical activity, age, height, genetics, hormonal status, medications and body composition are often more important than sex alone when determining individual calorie needs. E.g., a tall athletic woman with a larger frame and who lifts weights will demand as many calories or more than moderate-sized men who aren’t that active, for example.

2. Protein

Men generally need more total grams of protein because of their larger average body size and muscle mass. However, women don't inherently need less protein relative to their body weight. Protein requirements are calculated in grams/kg and range from 1-2g/kg for both men and women, depending on age, goals, activities, etc. Smaller women may need less protein than men because of their body size, but this is not always the case.

Both benefit from adequate protein to support muscle health, tissue maintenance and healthy aging. Protein becomes particularly important for women during and after menopause, when hormonal changes can contribute to normal muscle loss and changes in body composition.

3. Fiber

Men generally have higher daily fiber recommendations because their average calorie needs are greater. For adults ages 19–50, the recommended intake is approximately 38 grams daily for men and 25 grams for women.

Fiber supports digestive regularity, healthy cholesterol levels, blood sugar management and satiety. Please note that both sexes frequently fall short of their recommended intake, making fiber-rich foods such as vegetables, fruits, legumes and whole grains important.

4. Iron

Iron is one of the most significant nutritional differences between men and women. Women ages 19–50 generally need at least 18 milligrams daily, compared with just 8 milligrams for adult men, largely because of menstrual blood loss. Women who menstruate heavily, are pregnant or follow plant-based diets may need particular attention to iron intake.

While iron is the essential mineral your body uses to make red blood cells and transport oxygen throughout the body, ferritin is the storage protein that holds iron safely inside your cells. Low ferritin levels is the precursor to low iron levels and anemia. It makes you feel pretty rotten — tired, foggy and more susceptible to negative health impacts.

In fact, the American Society of Hematology in September 2026 established a higher serum ferritin threshold of 30 ng/mL or lower (increased from the previous ≤ 15 ng/mL) to note iron deficiency in menstruating or pregnant adults. For women in high-risk groups (heavy menstrual bleeding, pregnant with anemia), it’s now 50 ng/mL or lower. They aim to catch iron deficiency earlier, ideally well before issues develop.

5. Reproductive nutrients

Women's nutritional requirements change considerably during pregnancy and breastfeeding. Nutrients such as folate, iron, iodine, choline and vitamin B12 are particularly important for supporting fetal development and maternal health.

For men, nutrients such as zinc, selenium and folate contribute to normal reproductive function, including sperm production and development. However, note that consuming extra amounts of these nutrients hasn't consistently been shown to support fertility in people who already meet their nutritional needs.

6. Bone health

Both men and women need adequate calcium, vitamin D, protein and other nutrients to maintain strong bones. However, women face a greater risk of bone issues, particularly after menopause, when declining estrogen levels accelerate bone issues.

Women ages 51 and older are advised to consume 1,200 milligrams of calcium daily, compared with 1,000 milligrams for men through age 70. Men also experience age-related bone issues, but it generally occurs more gradually, with their calcium recommendation increasing to 1,200 milligrams at age 71.

7. Fuel use and appetite

Men and women differ somewhat in how their bodies store and use energy. Women generally have a higher percentage of body fat and tend to rely proportionally more on fat oxidation during moderate-intensity endurance exercise, while men often rely more heavily on carbohydrate oxidation at comparable relative exercise intensities. However, these differences don't necessarily translate into greater fat loss for either sex.

In general, men are more likely to have a bit of a belly and be more metabolically unhealthy. For women, the fat accumulation is more concentrated around the hips which tends to be more protective.

Hormones also influence appetite and eating patterns. In women, fluctuations in estrogen and progesterone across the menstrual cycle can affect hunger, cravings and energy intake, with some studies suggesting increased appetite during the luteal phase. Men generally experience fewer cyclical reproductive-hormone fluctuations, although appetite in both sexes is strongly influenced by sleep, stress, exercise and overall energy balance.

Vitamins and minerals that both men and women can come up short on

When you examine the data, you’ll note that many women and men can experience the same nutrient shortfalls. In particular, a 2025 study called “Sex differences in nutrient gaps among active adults” published in Journal of Nutritional Science found that there were five major vitamins and minerals that both sexes often didn’t get enough of — measured in Estimated Average Requirement (EAR).

Image source: Tinsley et. al

Note: Dietary intake + supplements were accounted for in the study above.

1. Vitamin D

It’s very challenging to get enough vitamin D through diet alone, while sun exposure to boost vitamin D levels isn’t practical or even possible for many. Therefore, it’s not a huge shock that most people are deficient.

In particular, 93 percent of women fall below the Estimated Average Requirement (EAR) while 88 percent of men do.

Women and men need vitamin D for bone/skeletal health, as it helps the body absorb calcium (an essential mineral for healthy bones). It also helps with immune system health and more, depending on the formulation.

Women and men aged 19 to 70 need 15 mcg (600 IU) while those over age 70 need 20 mcg (800 IU).

Supplement suggestions:

For supplements, you’ll notice that vitamins D3 and K2 are often paired because they play complementary roles in calcium support. Ancient Nutrition’s Liposomal Vitamin D3 + K2 Gel Packs (pineapple flavor) provide 4,000 IU (100 mcg) of vitamin D3 and 180 mcg of vitamin K2.

Meanwhile, Ancient Nutrients Vitamin D3 + K2 Capsules contain 5,000 IU (125 mcg) of probiotic-fermented vitamin D3 and 95 mcg of vitamin K ( (as MK-7) per serving.

Note that taking a multivitamin will usually cover one’s daily requirement, including 49 mcg (244% DV) in both Ancient Multivitamin Women's Once Daily and Ancient Multivitamin Women's 40+ Once Daily … or 100 mcg (500% DV) in Ancient Multivitamin Men's Once Daily and 40 mcg (200% DV) in Ancient Multivitamin Men’s 40+ Once Daily.

2. Vitamin C

With the plethora of vitamin C foods and how often this nutrient is talked about, it’s surprising that many people come up short. But 58 percent of women fall below the EAR while 64 percent of men do. Note that higher rates of dietary insufficiency are particularly seen among lower-income populations or those on restricted diets.

Vitamin C provides antioxidant support and more for both men and women, depending on the formulation.

Adult men need 90 mg of vitamin C per day, and adult women need 75 mg per day.

Supplement suggestions:

Ancient Nutrition’s Vitamin C supplement is not only formulated from real food, but also fermented with probiotics. It contains 900 mg (100% DV) per serving. Meanwhile, some multivitamins may contain over 100% DV such as Women's Fermented Multivitamin or Men’s Fermented Multivitamin, both of which contain 236 mg (260%).

3. Vitamin E

Low vitamin E intake is relatively common in both men and women. Overall, a surprising 77 percent of women fall below the EAR while 61 percent of men do.

It’s important to note that clinically diagnosed vitamin E deficiency is rare. People who eat few nuts, seeds, vegetable oils and leafy greens may have lower intakes.

Vitamin E is a fat-soluble antioxidant that helps promote overall health.

The Recommended Dietary Allowance (RDA) for vitamin E is 15 mg per day.

Supplement suggestions:

Ancient Nutrition’s multivitamins for women all contain 23.6 mg (157% DV) while the men’s vary in amounts but always go above 24 mg.

4. Magnesium

Magnesium is a common deficiency for both women and men. It's especially common among pregnant women (up to 80 percent according to one study) and women with hormone issues (up to 55 percent). Otherwise, up to 74 percent of women of fertile age may be short in magnesium.

Meanwhile, most men (up to 60 percent) don’t reach the recommended daily intake for magnesium, and it’s particularly important for men as they get older, such as over the age of 70.

On a global scale, there’s evidence suggesting that soil depletion has resulted in many crops being lower in magnesium than in past generations.

Magnesium plays a part in regulating calcium, potassium and sodium levels, thereby supporting overall health and wellness.

The RDA for magnesium in men aged 19 to 30 is 400 mg and men aged 31 and older need 420 mg. For women, it's 310–320 mg for nonpregnant women and 350–360 mg for pregnant women.

Supplement suggestions:

Only low levels of magnesium are typically included in multivitamins. Formulated with real food sources and optimized for absorption, Ancient Nutrients Magnesium contains 300 mg (71% DV) of magnesium in addition to 25 mcg of vitamin D.

Ancient Nutrition’s Active Peptides Magnesium Complex (capsule and powder forms) combines four highly bioavailable forms of magnesium, clinically validated ashwagandha and other supporting nutrients designed to help with stress, sleep, mood and energy. Magnesium Complex contains 320 mg (76% DV) of magnesium.

5. Vitamin A

A vitamin A shortage is relatively uncommon in healthy men and women in the U.S., although both sexes may consume less than the recommended daily amount. Overall, 55 percent of women fall below the EAR while 38 percent of men do.

Both men and women may be at greater risk of inadequate vitamin A intake if their diets lack foods such as eggs, dairy products, leafy greens, carrots and sweet potatoes. Vitamin A supports overall health.

The recommended daily intake is 900 mcg RAE (Retinol Activity Equivalents) for adult men and 700 mcg RAE for adult women. When pregnant, the needs go up 770 mcg RAE and for breastfeeding women it’s 1,300 mcg RAE.

Supplement suggestions:

Ancient Multivitamin Women's and Ancient Multivitamin Women's 40+ contain 2890 mcg (322% DV), while Ancient Multivitamin Men’s and Ancient Multivitamin Men’s 40+ contain 2930 mcg (325% DV).

6. Omega-3s

While not a vitamin or mineral, omega-3s are a common nutrient shortage for both men and women. They’re particularly lacking the long-chain omega-3 fatty acids EPA and DHA, which are found primarily in fatty fish and seafood. These essential fats support cardiovascular health, cognitive function and joint health.

Men generally need more of the plant-based omega-3 ALA, with an adequate intake of 1.6 grams daily compared with 1.1 grams for adult women. However, there is no established U.S. recommended daily allowance for EPA and DHA specifically. Both sexes may consume inadequate amounts if they rarely eat salmon, sardines, trout or other fatty fish.

Women have additional omega-3 considerations during pregnancy and breastfeeding, when DHA is particularly important for fetal and infant brain and eye development. Men also benefit from adequate omega-3 intake, especially for cardiovascular health.

Supplement suggestions:

Ancient Omegas Whole Body formula provides 1,000 milligrams of omega-3s (including 585 mg of ALA, 399 mg of DHA and 90 mg of EPA) from both wild ocean and plant-based sources.

Vitamins and minerals that more women than men lack in their diet

Women may be more likely than men to have inadequate intakes or deficiencies of these six vitamins and minerals — calcium, folate, iron, copper, B12 and zinc — because of differences in reproductive biology, hormonal changes, dietary habits and nutritional needs throughout life. In addition, some women aren’t eating enough nutrient-dense foods or simply eat too little.

In particular, menstruation, pregnancy, breastfeeding and menopause can all influence nutrient requirements, while women's generally lower calorie intake may make it more challenging to obtain adequate amounts of certain nutrients.

Recommended Daily Allowances

Note: A Recommended Dietary Allowance (RDA) is the average daily dietary intake level that is considered by the National Institutes of Health (NIH) Office of Dietary Supplements sufficient to meet the nutrient requirements of nearly all (97% to 98%) healthy individuals in a specific life stage and gender group.

* These nutrients have an AI (adequate intake) vs. RDA because there's not enough evidence to provide an RDA.

1. Calcium

Overall, 56 percent of women fall below the EAR for calcium. Calcium absorption can decline with age, while low vitamin D levels and certain compounds in plant foods, such as phytates and oxalates, can further reduce absorption. Women over 50, particularly after menopause, need to pay special attention to calcium intake to support bone health.

Those who avoid dairy because of lactose intolerance or a vegan diet may also be at greater risk of inadequate calcium intake, making calcium-rich foods and adequate vitamin D especially important.

Women require a relatively high amount of this mineral in comparison to many other trace minerals. Calcium is needed for healthy bones. After that age, it remains important for bone health.

The RDA for calcium is 1,000 mg for women ages 19 to 50 and 1,200 mg for women ages 51 to 70.

Supplement suggestions:

Calcium does not appear in a significant amount in any multivitamin because it’d make the multi size too large. Instead, to supplement, it’s best to use a body-ready, food-sourced form of calcium made without dairy like Ancient Nutrients Calcium. It also features vitamin D3, which, in general, is a preferred form of vitamin D and acts as a supporting role in the body’s absorption of calcium.

2. Folate

Folate is another common shortfall for women, with 58 percent falling below the EAR. Folate (vitamin B9) is especially important for women of reproductive age, as it supports healthy fertility, prenatal health, postnatal health and cognitive health. It also plays essential roles in cognitive health, blood folate concentration and total serum homocysteine levels.

Women who don't consume enough folate-rich foods or fortified products may be at greater risk of inadequate intake, particularly if they don't take supplements containing folic acid.

The RDA of folate is 400 mcg for non-pregnant women, 600 mcg for pregnant women and 500 mcg for breastfeeding women.

Supplement suggestions:

All of Ancient Nutrition's multivitamins for women contain 892 mcg DFE (223% DV) of folate (fermented folic acid). Additionally, the American Thyroid Association also suggests all prenatal vitamins contain 150 micrograms of iodine, which should be taken during pregnancy and afterward while breastfeeding. Most prenatal multivitamins usually cover one’s daily requirement for both folate and iodine.

3. Iron

An iron shortage is common worldwide, particularly among women, of whom 27 percent fall below the EAR. Iron needs increase during menstruation and pregnancy.

Iron is essential for producing hemoglobin, which carries oxygen throughout the body, and supports immune function, energy metabolism and physical performance. Women with heavy menstrual periods and pregnant women are especially at risk of inadequate iron levels. (See the American Society of Hematology reference above.)

The RDA for iron is 18 mg per day for women aged 19–50, 8 mg per day for women aged 51 and older, 27 mg per day for pregnant women, and 9 mg per day for breastfeeding women over age 18.

Supplement suggestions:

Ancient Nutrients Iron contains 18 mg (100% DV*) of enzyme-activated iron and is formulated with real food sources. Some multivitamins do contain the RDA of iron, but check each label to make sure. Ancient Multivitamin Women's contains 18 mg (100% DV) while Ancient Multivitamin Women's 40+ contains 6 mg (33% DV).

4. Vitamin B12

Vitamin B12 shortfalls can affect both men and women, particularly those following vegan or vegetarian diets, since B12 is found primarily in animal foods and fortified products. That being said, in the study named above, 27 percent of women fall below the EAR while only 4 percent of men do.

Women's B12 requirements increase during pregnancy and breastfeeding. This essential vitamin supports healthy cellular energy production, cognitive health, cardiovascular health, neurological health, eye health and more restful sleep. Older adults and people with absorption difficulties may also be at greater risk of a shortage.

The RDA for vitamin B12 is at least 2.4 mcg for women aged 19 and older, 2.6 mcg for pregnant women and 2.8 mcg for breastfeeding women.

Supplement suggestions:

For most, taking a multivitamin — such as 9.4 mcg (392% DV) of vitamin B12 in Ancient Multivitamin Women's Once Daily as well as Ancient Multivitamin Women's 40+ Once Daily — will more than cover your daily requirement.

If you’re a vegan or vegetarian, you may want to take a vegan B12 supplement (such as in the form of methylcobalamin), which is usually made via bacterial fermentation. Ancient Nutrition's non-vegan B12 supplement contains 20 mcg (833% DV) of vitamin B12.

5. Iodine

According to the CDC, women between the ages of 20–39 have the lowest urine iodine levels compared to all other age groups. The thyroid gland requires iodine to produce the hormones T3 and T4, which help control your metabolism.

Iodine intake is especially important for young women looking to become pregnant or who are pregnant.

The RDA of iodine is 150 mcg for non-pregnant women, 220 mcg for pregnant women and 290 mcg for breastfeeding women.

Supplement suggestions:

Most multivitamins — such as 159 mcg (110% DV) in Ancient Nutrition's Women's Fermented Multivitamin — will usually cover one’s daily requirement for iodine.

6. Zinc

Men actually require more zinc than nonpregnant women — 11 milligrams versus 8 milligrams daily. However, women's requirements increase to 11 milligrams during pregnancy and 12 milligrams during breastfeeding.

Women consuming diets low in meat and seafood may have difficulty meeting their needs, particularly because zinc from plant foods can be less readily absorbed. The study above shows that 30 percent of women fall below the EAR while only 8 percent of men do.

Supplement suggestions:

Most women’s multivitamins contain an adequate amount of zinc. Ancient Multivitamin Women's and Ancient Multivitamin Women's 40+ contain 10 mg (91% DV). Otherwise, Ancient Nutrients - Zinc + Probiotics is a vegan-friendly supplement that contains 20 mg (182% DV) of enzyme-activated zinc and 2 billion CFUs* (*at time of manufacture).

7. Copper

Women have the same recommended daily intake of 900 micrograms as men, but can be more lacking, with 34 percent falling below the EAR.

Copper requirements increase during pregnancy (1,000 micrograms) and breastfeeding (1,300 micrograms). Women with inadequate dietary intake, malabsorption issues or excessive zinc supplementation may be at greater risk of a copper shortage.

Supplement suggestions:

Many multivitamins don’t contain copper because it’s not been considered a common nutrient shortfall.

Frequently asked questions

How many more calories, generally, do women need to eat when pregnant?

First trimester, eat as normal. Second, roughly 340 calories more. Third, around 450 calories a day. However, you should always consult your healthcare professional.

For male and female couples, any advice for eating together beyond portion sizes?

Nutrition needs are not one-size-fits-all for either men or women and recommendations should always be personalized. That being said, men and women can eat the same meal, however, one person may need smaller portions, or to complement their meal with certain foods (ex: adding hemp seeds to increase iron content for women, adding another serving of carb for a very active man, etc.) to better suit their needs.

Are there supplements women sometimes shy away from that men don't?

Creatine and whey protein have historically been thought of as supplements for bodybuilders and ‘gym bros’, but we are finally getting away from that stereotype and recognizing the muscle benefits for both groups.

Creatine is one of the most well-researched supplements on the market, with benefits extending beyond just muscle strength and power. Creatine is also linked with brain benefits, including improved memory.

Are there supplements men might shy away from that women don't?

Collagen, calcium, iron and probiotics are good examples of supplements that have traditionally skewed more female, despite the fact that they can benefit women and men in certain situations.

Conclusion

Women and men share many of the same fundamental nutritional needs, but differences in body composition, hormones, reproductive biology and aging directly influence how much of certain nutrients they require. This is why it’s smart to individualize your diet towards your needs, not just sex alone. That’s the most effective (and strategic) approach to supporting long-term health as well as short-term goals.

Edwina Clark, RD, is a registered dietitian, foodie and fitness-junkie on a mission to help others lead healthy and happy lives. Her clinical training experience includes weight management, diabetes, gut health, allergies and sports nutrition. Now based in Alexandria, Virginia, this proud Australian has over a decade of experience bringing evidence-based health and wellness products to market. Edwina is an Ancient Nutrition paid partner and part of Ancient Nutrition's Wellness Roundtable.