Vitamins to take in winter, autumn and spring in the UK: what you actually need

What to take each season

In the UK, the one seasonal supplement with a clear rationale is vitamin D from October to March. Vitamin C, zinc, iron and the B vitamins don’t depend on the time of year. Your diet or a blood test decides those, not the calendar.

Vitamin D is different, because your skin makes most of it from ultraviolet B light. When the sun is low, there’s hardly any UVB even on a clear day. Vitamins from food don’t work like that: cabbage, carrots, eggs, fish and frozen berries are available all year.

Autumn vitamins: start vitamin D in October

As the days shorten, vitamin D production falls. The NHS says that between October and early March we don’t make enough vitamin D from sunlight. So it advises everyone, including pregnant and breastfeeding women, to consider a daily supplement of 10 micrograms (400 IU) in autumn and winter.

This applies across the UK, and the further north you live, the longer the dark season lasts. You can check the months for your city in our vitamin D sunlight calendar.

Women and children who qualify for the Healthy Start scheme can get free supplements containing vitamin D. If you qualify, use those first.

What to do in autumn:

• Start vitamin D in October unless you’re heading somewhere sunny for the winter.
• If you already take a multivitamin, check how much vitamin D it contains so you don’t double up.
• Skip “autumn immune” bundles: they’re often heavy on vitamin C and zinc and light on vitamin D.

Vitamins to take in winter

Keep taking vitamin D. For adults the NHS dose is 10 micrograms a day, and the upper limit is 100 micrograms (4,000 IU). More on doses, drops and capsules in our guide to how much vitamin D3 to take.

If you’ve got a tub of D3 in the kitchen cupboard and a multivitamin too, add them up:

Popular winter cold remedies do less than the adverts suggest.

• Vitamin C. According to Cochrane, taking it regularly doesn’t reduce your risk of colds. It shortens them by about 8% in adults, but only if you were already taking it. More in our vitamin C guide.
• Zinc. Zinc lozenges started within 24 hours shortened colds in some trials. Long-term high doses are harmful. See our zinc guide.
• Vitamin D for colds. An updated 2025 meta-analysis in The Lancet Diabetes & Endocrinology found no significant reduction in respiratory infections. Take vitamin D for bones and muscles when sunlight is short.

Sleep, physical activity, fresh air, handwashing and the vaccines you’re offered do more for winter illness than any bottle.

Spring: no such thing as a spring deficiency

You’ll sometimes hear that people run low on vitamins by spring. With a varied diet, they don’t. Stores of most vitamins last, and fruit and vegetables are on sale all year.

One real spring issue remains: March is still short of sunlight. The NHS says most people make enough vitamin D again from late March or April. So carry on with vitamin D until then.

If you’re constantly tired in spring, “low vitamins” is an unlikely cause. Poor sleep, iron deficiency and thyroid problems are more common, and a GP can test for them. See our guides to iron tablets and vitamin D tests.

Summer: sunlight and food

From late March or April to the end of September, most people make enough vitamin D if they spend time outdoors. Sunscreen and darker skin reduce how much you make, which is why some people need vitamin D all year.

Your year at a glance

Who needs vitamin D all year round

NHS advice is to take vitamin D every day, all year, if you are in one of these groups.

• People who are rarely outdoors, including care home residents.
• People who usually cover most of their skin outdoors.
• People with dark skin, for example of African, African-Caribbean or South Asian background.
• Children aged 1 to 4 and most babies – see our guide to vitamins for kids.

Food first in the colder months

Winter and spring meals can cover everything else:

• Vitamin C comes from citrus fruit, kiwi fruit, peppers, broccoli, sauerkraut and frozen berries. The NHS says you should be able to get all the vitamin C you need from a varied, balanced diet.
• Vitamin D is found in oily fish, egg yolks, liver and fortified foods. In the UK, cows’ milk generally isn’t fortified. Food alone rarely covers your needs, which is why the supplement advice exists.
• Iron and B12 come from meat, fish, eggs and pulses. Vegans need a B12 source all year, whatever the season.

Who should check with a doctor first

Taking too much vitamin D over a long period can cause hypercalcaemia, a build-up of calcium in the blood. The NHS says this can weaken bones and damage the kidneys and heart. Don’t exceed 100 micrograms (4,000 IU) a day unless a doctor advises it.

Talk to your GP or pharmacist before taking vitamin D in these situations.

• Kidney disease, kidney stones or high blood calcium.
• Sarcoidosis or another granulomatous condition.
• Medicines that affect calcium, such as some diuretics or heart medicines.
• Pregnancy: the dose is usually the same, but confirm it with your midwife.

You can check other combinations in our vitamin compatibility chart.

How to choose a winter vitamin on iHerb

1. Choose plain vitamin D3 rather than a seasonal bundle.
2. Check the dose per capsule or drop: 400 IU (10 micrograms) matches NHS advice.
3. If the bottle is 5,000 IU, don’t take one every day without medical advice.
4. Work out how many doses you need: October to March is about 180 days.
5. Order in good time; see our guide to iHerb UK delivery for shipping and VAT.