Nutrition for Women: Iron, Folate, Calcium and Vitamin D
Iron, folate and folic acid, calcium and vitamin D for women: food sources, who is more likely to run low, when testing helps, and the risks of taking too much.
Content last updated . This page has not been medically reviewed.
Food first, test before guessing
Several nutrients matter at different points in a woman's life: iron with periods and pregnancy, folic acid before and during pregnancy, and calcium and vitamin D for bones. This page gives an overview from public health sources. It does not tell you how much to take, because needs depend on age, diet, health conditions and medicines. Supplement profiles are in the Vitamins and Supplements section. Evidence labels: established recommendation, promising but limited, insufficient evidence.The four nutrients at a glance
| Nutrient | Why it matters | Who may be more likely to run low | Main caution |
|---|---|---|---|
| Iron | Used to make hemoglobin, which carries oxygen in red blood cells. [1] | People with heavy periods, pregnancy or breastfeeding, frequent blood donation, and some digestive conditions. [1] | Too much can cause constipation, nausea and, at very high levels, serious harm. [1] |
| Folate / folic acid | A B vitamin that helps the body make healthy new cells. [2] | Everyone needs it, and it is especially important for women who may get pregnant. [2] | Supplements in pregnancy: follow clinician advice, since higher doses are prescribed only in some situations. [3] |
| Calcium | Builds and maintains bones and helps muscles and nerves work. [4] | Varies; MedlinePlus lists groups who may find it hard to get enough. [4] | Calcium supplements may cause gas, bloating and constipation. [4] |
| Vitamin D | Helps absorb calcium; few foods contain it naturally. [5] | Older adults, people with dark skin, some digestive conditions, and obesity or gastric bypass. [5] | A test can show whether a supplement is needed. [5] |
Iron
Iron is found in lean meat, seafood, poultry, fortified cereals and breads, beans, lentils, nuts and some dried fruits. [1] See legumes and leafy greens. MedlinePlus says most people in the US get enough iron, but heavy periods raise the chance of low iron. [1] Low iron can cause iron deficiency anemia, with fatigue, shortness of breath and trouble concentrating. [1] The NHS says a clinician usually confirms iron deficiency anemia with a blood test before recommending iron tablets. [6] For the role of heavy bleeding, see heavy and irregular periods. During pregnancy, iron levels are checked at routine blood tests. [3]Safety: iron supplements can be harmful in excess, and a hereditary condition called hemochromatosis causes iron to build up. [1] See reading supplement labels.
Folate and folic acid
Folic acid is a B vitamin that helps the body make healthy new cells, and it comes from food or supplements. [2] Getting enough before and during pregnancy can prevent major birth defects of the brain or spine. [2] A Cochrane review of five trials with 7,391 women found daily folic acid supplementation protected against neural tube defects (high-quality evidence). [7] The NHS advises 400 micrograms daily starting ideally 3 months before pregnancy through the first 12 weeks, because it is difficult to get that amount from food alone, and a higher prescribed dose in specific situations. [3] Foods include leafy green vegetables, fruits, beans, peas, nuts, and enriched breads and cereals. [2] See fortified foods. Details are on preconception, pregnancy and postpartum.Calcium and vitamin D
Dairy products are the main calcium source for most people in the US, and leafy greens, soft-boned fish and fortified foods also contribute. [4] See yogurt. MedlinePlus lists recommended calcium of 1,000 mg a day for adults 19 to 50 and 1,200 mg for women 51 to 70, and says calcium is absorbed best at 500 mg or less at one time. [4] It lists vitamin D at 600 IU a day for adults 19 to 70, from skin exposure to sunlight, fortified foods or supplements. [5] These are general recommended intakes, not personal targets.The NHS suggests calcium-rich foods and weight-bearing exercise to support bones in menopause. [8] A 2026 review found moderate-certainty evidence that vitamin D reduces fracture risk and high-certainty evidence for its safety. [9] More in osteoporosis and bone health and vitamin C, vitamin D and zinc.
Supplements and PMS
Calcium, vitamin D, vitamin B6 and magnesium are sometimes taken for PMS; the NHS says there is not much evidence that they work. [10] See PMS and PMDD.When to get help
Ask a clinician about testing if you have heavy periods with tiredness or breathlessness, if you are planning a pregnancy, or if you have conditions affecting absorption. [1][3] Check medication interactions and amounts and duplicate ingredients before combining products.Frequently asked questions
Should every woman take iron?
No. Most US adults get enough iron, and too much can cause harm. Testing helps. [1]
Do I need folic acid if I am not pregnant?
Folic acid matters most for people who could become pregnant. [2]
Is calcium from food better than supplements?
MedlinePlus says you may be able to get enough calcium from a variety of foods, and that supplements can cause gas, bloating or constipation in some people. [4]
Can vitamin D be taken in any amount?
No. A test can show if a supplement is needed. The NHS also warns that very high amounts can be harmful. [5][3]
References
- MedlinePlus. Iron. Read 2026-10-22.
- MedlinePlus. Folic acid. Read 2026-10-22.
- NHS. Pregnancy vitamins and supplements. Read 2026-10-22.
- MedlinePlus. Calcium. Read 2026-10-22.
- MedlinePlus. Vitamin D. Read 2026-10-22.
- NHS. Iron deficiency anaemia. Read 2026-10-22.
- De-Regil LM, et al. Effects and safety of periconceptional oral folate supplementation for preventing birth defects. Cochrane Database Syst Rev. 2015. PubMed. Read 2026-10-22.
- NHS. Things you can do to help menopause and perimenopause symptoms. Read 2026-10-22.
- Complementary therapies for management of menopausal symptoms: a systematic review to inform the update of the International Menopause Society guidelines. Climacteric. 2026. PubMed. Read 2026-10-22.
- NHS. PMS (premenstrual syndrome). Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.