Who May Need Supplements: Pregnancy, Babies, Vegans and Older Adults

Nutrition · Published 2026-10-24

A breakfast plate of seeded bread, orange juice, olives, guacamole and sun-dried tomatoes — A breakfast plate, seen from above.

Health authorities do not recommend supplements for everyone. They recommend specific nutrients for specific groups, where food alone reliably falls short. This page brings those recommendations together, with the official source for each.

Before anything else

The recommendations below are for groups, not individuals. Whether you personally need a supplement, and how much, depends on your diet, health, medicines and sometimes blood tests. A doctor, pharmacist, midwife, health visitor or registered dietitian can advise. Where a recommendation includes an amount, it is the amount stated by the official body cited, not a dose suggested by this site.

Planning a pregnancy, pregnancy and breastfeeding

Folic acid. The NHS advises 400 micrograms a day from before conception until 12 weeks of pregnancy, to reduce the risk of neural tube defects; some people at higher risk are prescribed 5 mg. The US Preventive Services Task Force recommends 400 to 800 micrograms daily for anyone planning or capable of pregnancy. See folate and folic acid.
Vitamin D. The NHS advises 10 micrograms a day during pregnancy and breastfeeding.
Avoid vitamin A supplements (and fish liver oils, liver and liver products) during pregnancy, as high intakes of retinol can harm the developing baby. Pregnancy-specific multivitamins are formulated to avoid this.
Iron is not routinely recommended to all pregnant people in the UK; it is prescribed when blood tests show deficiency. Some other countries and the WHO, particularly where anaemia is common, recommend routine iron and folic acid supplements in pregnancy.
Iodine needs rise in pregnancy. Practice differs: the American Thyroid Association recommends that pregnant and breastfeeding women in the US and Canada take a supplement containing 150 micrograms of iodine daily, while the NHS does not routinely recommend one and advises getting iodine from foods such as dairy and fish. People on plant-based diets should discuss iodine with their midwife or doctor. High-iodine products such as kelp supplements are not suitable.

Babies and young children

Breastfed babies: the NHS advises a daily vitamin D supplement of 8.5 to 10 micrograms from birth. Babies having more than 500 ml of infant formula a day should not be given additional vitamin D, because formula is fortified. In the US, the American Academy of Pediatrics recommends 400 IU (10 micrograms) of vitamin D daily for breastfed and partially breastfed infants.
Children aged six months to five years: the NHS recommends daily supplements containing vitamins A, C and D, unless the child drinks more than 500 ml of formula a day. In the UK these are available free to eligible families through the Healthy Start scheme.
Keep all supplements, especially those containing iron, out of children's reach; accidental iron overdose is dangerous for young children.

Vegans and some vegetarians

Vitamin B12 is essential: vegan diets contain no reliable natural source, so fortified foods or a supplement are needed. This is the consistent position of the NHS and of dietetic associations. See vitamin B12.
Iodine: in countries without iodised salt, such as the UK, dairy and fish are major sources. Many plant milks are not fortified with iodine, so vegans may need a fortified product or supplement; the NHS advises against using seaweed as a source because its iodine content is highly variable and can be excessive.
Vitamin D, calcium and omega-3 (EPA/DHA) need attention; fortified foods and algae-based sources can help. Iron and zinc are generally adequate in well-planned vegan diets but should be considered, particularly for menstruating people.

Older adults

Vitamin D: the US RDA rises to 20 micrograms (800 IU) after age 70. People who are housebound or in care homes are among the groups the NHS advises to consider vitamin D all year round. The Endocrine Society's 2024 guideline suggests empiric vitamin D for adults aged 75 and over.
Vitamin B12: because stomach acid often falls with age, the US National Academies advise people over 50 to obtain most of their B12 from fortified foods or supplements.
Calcium and protein intake can decline with appetite; dietary advice is usually the first step, with supplements decided individually.

People with little sun exposure or darker skin

The NHS advises people who are rarely outdoors, who usually cover most of their skin when outside, or who have dark skin (for example of African, African-Caribbean or South Asian origin) to consider taking 10 micrograms of vitamin D a day throughout the year. See vitamin D.

Group	Nutrient	Official advice
Planning a pregnancy, up to 12 weeks	Folic acid	400 micrograms a day (NHS); 400–800 micrograms (USPSTF)
Pregnancy and breastfeeding	Vitamin D	10 micrograms a day (NHS)
Pregnancy and breastfeeding (US, Canada)	Iodine	150 micrograms a day (American Thyroid Association); not routine in the UK
Breastfed babies	Vitamin D	8.5–10 micrograms a day from birth (NHS); 400 IU, 10 micrograms (AAP)
Rarely outdoors, covered skin or dark skin	Vitamin D	Consider 10 micrograms a day all year (NHS)
Adults over 70 (US)	Vitamin D	RDA 20 micrograms (800 IU)

Summary of figures given above on this page; see Sources below.

Medical conditions and medicines

Supplements are often part of medical care in these situations, prescribed and monitored by clinicians:

malabsorption conditions such as coeliac disease, Crohn's disease, cystic fibrosis and chronic pancreatitis;
after bariatric (weight-loss) surgery, where lifelong supplementation with several nutrients is standard;
pernicious anaemia (vitamin B12 injections);
confirmed iron deficiency, for example from heavy menstrual bleeding (after the cause has been assessed);
long-term use of medicines that affect nutrient status, such as metformin (B12), proton pump inhibitors (B12, magnesium) and some anti-epileptic drugs (vitamin D, folate);
chronic kidney disease, where some supplements must be avoided and others are prescribed.

People with very restricted diets

People with eating disorders, alcohol dependence, severe food insecurity or very limited diets (including some autistic children with restricted eating) are at risk of multiple deficiencies, sometimes including scurvy and thiamine deficiency. They need medical and dietetic support rather than self-selected supplements.

Who generally does not need them

For healthy, non-pregnant adults who eat a varied diet, outside the groups and situations above, the evidence does not support routine supplements for preventing chronic disease. See do multivitamins work?

In short

Folic acid before and in early pregnancy, and vitamin D in pregnancy, infancy and for people with little sun, are the most widely recommended supplements.
Vegans need B12 and should think about iodine; older adults may need vitamin D and B12.
Medical conditions and some medicines change needs; these are managed by clinicians.
Outside these groups, a varied diet is the recommended source of vitamins and minerals.

This page is general information, not medical advice. Speak to a doctor, pharmacist, midwife or registered dietitian before starting a supplement for yourself or a child.

Sources

NHS, Vitamins and minerals, Vitamins in pregnancy and Vitamins for children.
NHS, The vegan diet.
NIH Office of Dietary Supplements, Dietary supplement fact sheets.
Alexander EK et al. 2017 Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum. Thyroid 2017;27(3):315–389.
Demay MB et al. Vitamin D for the prevention of disease: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2024.
World Health Organization, WHO recommendations on antenatal care for a positive pregnancy experience (2016).