How Much Vitamin D Do You Need?

How much vitamin D per day you need depends on your age: most adults need 15 micrograms (600 IU) a day, and adults over 70 need 20 micrograms (800 IU), according to the US National Institutes of Health. The European Food Safety Authority (EFSA) sets an adequate intake of 15 micrograms a day for everyone over one year old. Do not go above 100 micrograms (4,000 IU) a day without medical advice, and remember that in much of Europe winter sunlight is too weak to make vitamin D in your skin.

Vitamin D comes from three places: your skin, your food and, for many people, a supplement. Here are the official numbers by age, micrograms versus IU, the foods that actually contain it, and how to decide about a winter supplement.

How much vitamin D do you need daily?

US and European experts land on similar numbers. NIH sets Recommended Dietary Allowances (RDAs). EFSA’s Adequate Intakes (AIs) assume your skin makes almost no vitamin D.

Age group	NIH (US)	EFSA (EU)
Infants 0-12 months	10 µg (400 IU)	10 µg (400 IU), for 7-11 months
Children and teens 1-18 years	15 µg (600 IU)	15 µg (600 IU), for 1-17 years
Adults 19-70 years	15 µg (600 IU)	15 µg (600 IU)
Adults over 70	20 µg (800 IU)	15 µg (600 IU)
Pregnancy and breastfeeding	15 µg (600 IU)	15 µg (600 IU)

Source: NIH Office of Dietary Supplements, Vitamin D fact sheet; EFSA NDA Panel, Dietary reference values for vitamin D (2016). The NIH value for infants is an Adequate Intake.

These amounts cover nearly all healthy people. Treating a diagnosed deficiency is a separate job for your doctor.

What is the difference between micrograms and IU?

Labels use both. One microgram (µg or mcg) of vitamin D equals 40 international units (IU). A few conversions you will see on supplement boxes:

• 10 µg = 400 IU
• 25 µg = 1,000 IU
• 50 µg = 2,000 IU
• 100 µg = 4,000 IU, the adult upper limit

Can you get enough vitamin D from the sun in Europe?

In summer, often yes. NIH ODS notes that roughly 5 to 30 minutes of midday sun on face, arms and legs, without sunscreen, daily or at least twice a week, usually leads to enough synthesis. Season, time of day, cloud, skin colour and age all matter: older people and people with darker skin make less.

Winter is different. A classic 1988 study tested real sunlight. In Boston, at about 42 degrees north (close to the latitude of Rome, Barcelona or Sofia), skin samples made no vitamin D from November through February, even on clear days. In Edmonton, at about 52 degrees north (roughly Berlin or Amsterdam), the gap ran from October through March.

The NHS gives the same picture for the UK: sunlight works from about late March or early April to the end of September, but between October and early March it is not enough.

Two details people miss: UVB does not pass through window glass, and sunscreen of SPF 8 or more appears to block vitamin D production. NIH still advises SPF 15 or higher to protect your skin.

Which foods are high in vitamin D?

Very few foods contain much vitamin D. Oily fish leads, egg yolks and fortified foods help, and most plant foods contain none, except mushrooms exposed to UV light.

Food and portion	Vitamin D (µg)	IU
Cod liver oil, 1 tablespoon	34.0	1,360
Rainbow trout, farmed, cooked, 85 g (3 oz)	16.2	645
Sockeye salmon, cooked, 85 g (3 oz)	14.2	570
White mushrooms, UV-exposed, raw, sliced, half a cup	9.2	366
Fortified soy, almond or oat drink, 1 cup	2.5-3.6	100-144
Sardines in oil, drained, 2 fish	1.2	46
Egg, 1 large, scrambled	1.1	44
Light tuna, canned in water, 85 g (3 oz)	1.0	40
Cheddar cheese, 1.5 oz (about 42 g)	0.4	17
Lentils, almonds, broccoli, brown rice	0	0

Source: NIH Office of Dietary Supplements, Vitamin D fact sheet (US food data).

Fortification differs in Europe: the NHS notes that UK cow’s milk is generally not fortified, so check the label of your milk, plant drink or cereal. Ordinary mushrooms grown in the dark contain very little: a half cup of raw portabella gives only 0.1 µg.

One portion of trout covers a full day, an egg less than a tenth, so without oily fish 15 µg from food is hard to reach. A Mediterranean-style diet with fish helps. If you are plant-based, see our overview of the vegan diet’s benefits and risks.

How do you know if your vitamin D level is too low?

The blood test measures 25-hydroxyvitamin D, written 25(OH)D. NIH ODS uses these ranges:

• below 30 nmol/L (12 ng/mL): linked to deficiency, rickets in children and soft bones (osteomalacia) in adults,
• 30 to under 50 nmol/L (12 to under 20 ng/mL): generally inadequate for bone and overall health,
• 50 nmol/L (20 ng/mL) or more: adequate for most healthy people,
• above 125 nmol/L (50 ng/mL): linked to possible adverse effects.

EFSA uses 50 nmol/L as its target. Should everyone get tested? The Endocrine Society’s 2024 guideline suggests against routine testing in the healthy groups it studied, so test when your doctor has a medical reason.

How much vitamin D3 should you take daily in winter?

For most adults, 10 to 15 µg (400 to 600 IU) a day covers the gap. The NHS suggests everyone consider 10 µg in autumn and winter, and all year for people who are rarely outdoors, cover most of their skin or have dark skin.

More is not automatically better. The Endocrine Society’s 2024 guideline suggests healthy adults under 75 stay at the reference intakes. Groups that may benefit from more are children and teens, adults 75 and older, pregnant people and people with prediabetes, a decision for your doctor.

Supplements come as D2 or D3. Both raise blood levels, but NIH ODS notes that most evidence shows D3 raises 25(OH)D more and keeps it up longer. Vitamin D is fat-soluble, like vitamin A, so many people take it with a meal that contains some fat.

What does Ayurveda say about vitamin D and sunlight?

Ayurveda has no concept of vitamin D, but it has a strong sense of season and daily rhythm. The classical seasonal routine (ritucharya) for the cold months recommends warm clothing, oil massage and time in the sun, and describes winter as the season when agni, the digestive fire, is strongest. Heavier, nourishing foods with a little ghee or sesame are traditionally favoured then.

Strong sun is associated with pitta, the hot dosha, so midday summer sun was treated with respect. These are traditional ideas, not evidence about vitamin D, but the practical overlap is clear: get outside when the sun is strong enough, and do not rely on winter light.

How can you get more vitamin D from food? A winter trout tray bake

An 85 g cooked portion of farmed rainbow trout gives about 16 µg, a full day for most adults. Serves 2.

Ingredients:

• 2 rainbow trout fillets (about 150 g each)
• 400 g small potatoes, halved
• 250 g mushrooms, UV-treated if your shop sells them, thickly sliced
• 2 tablespoons olive oil
• 2 garlic cloves, sliced
• 1 lemon
• a small bunch of fresh dill, chopped
• salt and black pepper

1. Heat the oven to 200°C. Toss the potatoes with 1 tablespoon olive oil and a pinch of salt on a baking tray and roast for 20 minutes.
2. Add the mushrooms and garlic, drizzle with the remaining oil, stir and roast for 10 minutes more.
3. Lay the trout fillets skin side down on top, season, and add a few thin lemon slices.
4. Bake for 10 to 12 minutes, until the fish flakes easily.
5. Scatter with dill, squeeze over the rest of the lemon and serve with a green salad.

On vegetarian days, eggs help a little: try our high-protein vegetarian breakfast ideas or the list of healthy breakfast foods, though you will still be well short of 15 µg.

How much vitamin D is too much?

Anything regularly above 100 µg (4,000 IU) a day for adults, unless your doctor prescribes it. A 5,000 IU capsule is 125 µg, already over that limit. Toxicity almost always comes from supplements. Too much vitamin D raises blood calcium, which can cause nausea, vomiting, muscle weakness, confusion, pain, loss of appetite, dehydration, frequent urination, strong thirst and kidney stones. Extreme cases can end in kidney failure, heart rhythm problems or death. Toxicity usually comes with 25(OH)D above 375 nmol/L (150 ng/mL).

Age group	Upper limit, EFSA (EU)	Upper limit, NIH (US)
Children 1-10 years	50 µg (2,000 IU)	63-100 µg (2,500-4,000 IU), by age
Teens 11-17 years	100 µg (4,000 IU)	100 µg (4,000 IU)
Adults, including pregnancy and breastfeeding	100 µg (4,000 IU)	100 µg (4,000 IU)

Source: EFSA NDA Panel, Scientific opinion on the tolerable upper intake level for vitamin D (2023); NIH Office of Dietary Supplements.

For babies, NIH sets 25 µg (1,000 IU) up to 6 months and 38 µg (1,500 IU) from 7 to 12 months. Watch for stacking: a multivitamin, a separate vitamin D and fortified foods add up.

NIH ODS lists possible interactions with orlistat (a weight-loss drug that lowers absorption), statins, steroids and thiazide diuretics. If you take any of these, ask your pharmacist first.

Related reading: magnesium-rich foods for the rest of your winter plate, and our guide to high-quality fats.

FAQ

Is 1,000 IU or 2,000 IU of vitamin D a day too much?

For healthy adults, no. 1,000 IU is 25 µg and 2,000 IU is 50 µg, both under the adult upper limit of 100 µg (4,000 IU). For children aged 1 to 10, EFSA’s limit is 50 µg.

Can you get vitamin D through a window?

No. The UVB rays your skin needs do not pass through glass, so sitting in a sunny room does not produce vitamin D.

Is vitamin D3 better than D2?

Both work, but most evidence summarised by NIH ODS shows D3 raises blood 25(OH)D more and keeps it higher for longer.

How much vitamin D per day for a woman?

The same as for a man: 15 µg (600 IU) a day up to age 70 and 20 µg (800 IU) after that, according to NIH. Pregnancy and breastfeeding do not change the amount, which stays at 15 µg in both NIH and EFSA advice.

Sources

1. NIH Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. Updated 2026. ods.od.nih.gov
2. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Dietary reference values for vitamin D. EFSA Journal, 2016. efsa.europa.eu
3. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA). Scientific opinion on the tolerable upper intake level for vitamin D. EFSA Journal 21(8), 2023. EFSA Journal via DOAJ
4. NHS. Vitamin D. Vitamins and minerals. nhs.uk
5. Webb AR, Kline L, Holick MF. Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. Journal of Clinical Endocrinology and Metabolism, 1988. PubMed 2839537
6. Endocrine Society. Endocrine Society recommends healthy adults take the recommended daily allowance of vitamin D. 2024. endocrine.org

This article is for information only and is not medical advice. If you have a health condition, are pregnant or take medication, talk to your doctor or pharmacist before changing your diet or starting a supplement.