How to Choose a Multivitamin for Women: The Label by Life Stage

Choose a multivitamin for women by reading the label against UK reference values, not by the picture on the box: it should supply 10 micrograms of vitamin D, 400 micrograms of folic acid if you could become pregnant, iron only if you still have periods, no more than about 10 mg of vitamin B6, and no vitamin A in the retinol form if you are pregnant. Beyond that, most nutrients at 50 to 200% of the reference value are fine and anything at 1,000% or more is marketing. The first question, though, is whether you need one at all. Women eating a varied diet with dairy, fish or meat, vegetables and wholegrains mostly do not, and the large trials of multivitamins in healthy adults show little effect on disease.¹ The women who benefit are those with a narrow diet, vegans, women planning a pregnancy, women with heavy periods, and women over 65 eating less; for them a well-chosen multivitamin is a sensible hedge, and this page is how to choose it.

• Do you need one? Usually not on a varied diet; yes for a narrow or plant-based diet, pregnancy planning, heavy periods or older age
• Must have: vitamin D 10 micrograms; folic acid 400 micrograms if you could conceive; B12 if vegan or over 65
• Depends on age: iron before the menopause (14.8 mg reference); little or none after (8.7 mg)
• Limits: vitamin B6 under 10 mg; vitamin A under 1,500 micrograms and none as retinol in pregnancy; folic acid under 1 mg
• Ignore: "women's blend" botanicals, mega-doses, "energy" and "beauty" claims not on the authorised register

Do women need a multivitamin?

The NHS position is that most people get what they need from food and that the supplements with a case for everyone are vitamin D from October to March and folic acid for women who could become pregnant. The large placebo-controlled trials of daily multivitamins in healthy adults found no reduction in heart disease or cancer, and a recent trial found a modest benefit for memory in older adults that needs confirming.^{1, 2} So a multivitamin is not a health insurance policy for a good diet. It is a reasonable top-up when the diet is thin: women on restrictive or very low-calorie plans, vegans, women with heavy periods who lose iron, women who eat little fish, dairy or vegetables, and women over 65 with smaller appetites. If one of those describes you, choose well; if none does, spend the money on food. Our hub on vitamins and minerals sets out the UK reference values that the label percentages refer to.

What a women's multivitamin should contain

Read the "per daily dose" column and the percentage of the nutrient reference value, NRV, beside each nutrient. The NRV is a labelling figure, close to but not identical with the UK reference intake; 100% is a sensible target for most nutrients, more is not better.

• Vitamin D: 10 micrograms (400 IU), 200% NRV; 25 micrograms is fine. Vitamin D contributes to the maintenance of normal bones and teeth and muscle function and the normal function of the immune system.
• Folic acid: 400 micrograms (200% NRV) if you could become pregnant; 200 micrograms otherwise. Never above 1 mg without prescription.
• Vitamin B12: at least 2.5 micrograms; 10 to 50 if vegan or over 65. B12 contributes to normal red blood cell formation and the reduction of tiredness and fatigue.
• Iron: 10 to 14 mg before the menopause, especially with heavy periods; little or none after, unless a test shows you need it. Iron contributes to normal formation of red blood cells and haemoglobin.
• Iodine: 150 micrograms if you eat little dairy or fish, or are vegan; iodine contributes to normal thyroid function.
• Zinc, selenium, vitamin C, B vitamins: around 100% NRV. B6 at or below 10 mg.
• Calcium and magnesium: a multivitamin cannot fit useful doses of either; expect 10 to 30% NRV and get the rest from food.
• Vitamin A: under 800 micrograms, as beta-carotene rather than retinol if you are or may become pregnant, and none from liver-based products.

What changes at 40, 50 and 60

Up to the menopause. Iron matters, because periods cost it; 14.8 mg a day is the reference and a multivitamin with 10 to 14 mg is reasonable, with a ferritin test if you are tired. Folic acid matters if pregnancy is possible. Vitamin D as for everyone.

Through the menopause transition, roughly 45 to 55. Periods become irregular and often heavier for a time, so iron remains relevant until they stop. Bone loss accelerates in the years around the menopause, so vitamin D, calcium from food and protein and resistance exercise move up the list; magnesium and vitamin K contribute to the maintenance of normal bones too. No supplement treats menopause symptoms, and which menopause supplements have evidence reviews what the trials show.

After the menopause. Iron need falls to 8.7 mg and most post-menopausal women should not take an iron-containing multivitamin unless a test shows deficiency, because iron accumulates. B12 absorption falls from the mid-sixties, so B12 at 10 micrograms or more becomes the useful ingredient. Vitamin D all year if you are indoors more. "Women's 50+" formulas are built on exactly these changes: iron out, B12 and D up; check that yours follows the pattern. B12 for women covers the age and menopause questions in detail.

What to ignore on the label

Mega-doses: 1,000% of a B vitamin is excreted, and 5,000% of biotin interferes with blood tests. Botanical "women's blends" of cranberry, evening primrose, horsetail and the like at token doses with no authorised claims. "Energy", "beauty", "hormone balance" and "immune boost" wording; the only permitted claims are the authorised nutrient ones, and a brand that stretches them on the box is telling you how it reads the rules. Proprietary blends that hide individual doses. Gummies for minerals, where the dose will not fit; do vitamin gummies work explains. And price as a quality signal: the nutrients are commodities and the label, not the cost, tells you what you are getting.

When and how to take it

With a meal that contains some fat, which helps vitamins A, D, E and K absorb and prevents the nausea iron and zinc cause on an empty stomach. Any time of day; the "vitamins should not be taken at night" idea has no basis, since no vitamin is a stimulant. One a day is the design; do not double up for a missed day. If you also take a separate vitamin D, iron or B complex, add the doses together so the total stays sensible, particularly for vitamin A, B6, iron and folic acid.

Which vitamins cannot be taken together?

None dangerously, which is why multivitamins exist. The one real interaction is absorption: iron, calcium, zinc and magnesium compete when taken as large separate doses at the same time, so a high-dose iron tablet and a calcium tablet are better two hours apart, and iron away from tea, coffee and dairy. At the modest doses in a multivitamin this matters little. Vitamin C helps iron absorb. The "two vitamins you should never take together" and "five supplements never to combine" lists online are built on this timing point, inflated.

Side effects and who should check first

Nausea if taken on an empty stomach, bright yellow urine from riboflavin, and dark stools from iron are the common ones, all harmless. Women who are pregnant should take a pregnancy-specific product with folic acid and no retinol. Women with haemochromatosis should avoid iron. Anyone on warfarin should check the vitamin K content with their anticoagulant clinic, and anyone on levothyroxine should take it four hours from a multivitamin containing iron or calcium. Wellgard's women's multivitamin gummies and women's 50+ multivitamin gummies follow the pattern above, iron in the first and out of the second; the vitamin D in them contributes to the maintenance of normal bones and teeth, the B12 to the reduction of tiredness and fatigue, and the folate to normal blood formation.

What we don't know

• Whether daily multivitamins help healthy women long term. Disease trials say little; the memory signal in older adults needs confirming.^{1, 2}
• Whether "life stage" formulas outperform a plain one. The logic is sound; no trial has compared them.

Frequently asked questions

What should a multivitamin for women contain?

Vitamin D at 10 micrograms, folic acid at 400 micrograms if you could conceive, B12, iodine if you eat little dairy or fish, iron before the menopause, and other nutrients near 100% NRV with B6 under 10 mg.

Do women over 50 need a different multivitamin?

Usually one without iron and with more B12 and vitamin D, because iron need falls and B12 absorption declines. Check the label rather than the age on the box.

Should a women's multivitamin contain iron?

Before the menopause, a modest dose is reasonable, more so with heavy periods. After it, no, unless a blood test shows deficiency.

What are the top 3 vitamins to take daily?

For most women: vitamin D from October to March, folic acid if you could become pregnant, and B12 if vegan or over 65. Everything else depends on diet.

What is the best time to take a multivitamin?

With a meal containing some fat, at whatever time you will remember. Night is fine; no vitamin keeps you awake.

Sources

1. Fortmann SP, et al. Vitamin and mineral supplements in the primary prevention of cardiovascular disease and cancer: an updated systematic evidence review for the US Preventive Services Task Force. Annals of Internal Medicine, 2013. PubMed 24217421.
2. Vyas CM, et al. Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COSMOS trial and meta-analysis. American Journal of Clinical Nutrition, 2024. PubMed 38244989.
3. NHS. Vitamins and minerals. nhs.uk; NHS. Vitamins, supplements and nutrition in pregnancy. nhs.uk.
4. Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals, 2003. cot.food.gov.uk.

This article is general information, not medical advice. If you are pregnant, have haemochromatosis, take warfarin or levothyroxine, or have a diagnosed deficiency, ask your GP or pharmacist which supplement suits you.