Please select the country or location you would like to see content from.
country picker icon
condition icon


Do I need vitamins in winter?

Written by Caidr's team of doctors and pharmacists based in UK | Updated: 17.02.2023 | 8 min read

As the days get shorter and the temperature cools, it can be tempting to curl up on the sofa with some comfort food and a binge-worthy box set. But we are not naturally hibernating animals, so it's important to understand why your energy levels may dip while your appetite increases and address it with healthy choices.

The doctors at Caidr will always encourage a healthy balanced diet over and above taking supplements, and the more colorful and varied your meals, the more nourishing nutrients you get. But there are times that supplements may be helpful or even vital. There is less choice of fresh foods over winter and less sunshine to naturally make vitamin D, plus fighting off colds and flu means our immunity needs to be in tip-top condition.

Let's talk you through the challenges of winter and how to counter them to keep you healthy in mind and body.

Causes & triggers

Too little sunshine

Sunshine is thought to bring us happiness by boosting the production of the feel-good neurotransmitter serotonin. With depleted levels, it's thought that this contributes to a low mood. Sunlight also regulates the production of melatonin, a hormone known to induce sleep. Less sunshine means more melatonin and hence potentially more lethargy and over-sleeping in the winter.

Vitamin D deficiency

We get most of our vitamin D from sunlight, so the darker days of winter mean we risk becoming deficient. It's thought that vitamin D boosts serotonin levels, which work in the brain to elevate mood, so this may also play a role in the winter blues. It's recommended that everyone takes a supplement through the winter to benefit bones, teeth, muscles, and mood. Those spending lots of time indoors or of darker skin color should take one all year round. Certain foods also contain vitamin D, like oily fish, liver, egg yolks, or fortified cereals, but you'd have to eat a lot of them to get enough to compensate for winter sunlight levels.


Seasonal affective disorder (SAD) is a known phenomenon akin to depression that starts in autumn and builds as the winter comes. This can cause a persistent low mood, feelings of despair, worthlessness or hopelessness, lack of concentration and motivation, lack of pleasure in usually enjoyable activities, irritability, and increased sleepiness. This is related to a lack of sunshine. Still, the exact mechanism isn't well-understood – it may involve a reduction of serotonin, disruption to your circadian rhythm, which controls your sleep-wake cycle, and possibly increased melatonin. It doesn't affect everyone to the same extent; some may get a mild version, but for others, it can be pretty debilitating.

Too few fruits and vegetables

There are plenty of juicy bright fruit and vegetables in the summer harvest, bringing us lots of vitamins and minerals, but the choices are less appealing in winter and don't contain the same abundance of nutrients. So, we have to work harder to get nutrients from our diet, and many of the fruit and vegetables need to be cooked or flavored in other ways to appear palatable.

Craving comfort foods

We tend to seek more comfort food in winter, like pasta, bread, pastries, biscuits, and chocolate. These sugar-rich or carb-heavy foods make you feel full and satisfied for a short while but also sleepier and more lethargic. At the same time, your body diverts energy from brain activities like thinking and planning towards digesting instead. Swings of sugar from high to low can also disrupt our mood and sleep.

Less active

It's much easier to stay active in summer when it's warm, dry, and light in the mornings and evenings, but harder to motivate ourselves to exercise in the winter, especially outdoors. This may have something to do with our circadian rhythms, our sleep-wake cycle that finds it hard to be active at darker times of the day.


It's a myth to say that our metabolism goes down in winter – this is only true for hibernating animals – that's bears, not us. But there's an argument to say that we need more calories to generate warmth in the cold months, and this may explain our quest for the carbs.

Increased immune requirements

Viruses thrive in the autumn and winter, doing best in the cold weather and spending time indoors while we're in close proximity. Children going back to school or nursery in the autumn term heralds the start of the cough and cold season, and flu season starts mid-autumn, with COVID-19 as a new recruit to the parade of viral illnesses.

Low mood or depression

Aside from SAD, many suffer a dip in their mood for a combination of the factors above – missing the sunshine, feeling lethargic, and a lack of activities compared to warmer months. This can all add to a sluggish feeling during the winter.

Treatment: home & drug-free

Vitamin D: It's recommended that everyone takes a supplement through the winter to benefit bones, teeth, muscles, and mood, and those spending lots of time indoors or of darker skin color should take one all year round.

Vitamin B family: Vitamin B6 is thought to boost serotonin levels, so without enough onboard, we run the risk of depression. In older people, vitamin B12 helps with cognitive function and runs low in those with Alzheimer's disease and dementia, which suggests boosting this may help. It also suggests the role vitamin B may play in brain function, but we haven't discovered everything yet.

Magnesium: If winter brings you low energy levels and low mood to match, research has suggested magnesium may help improve your mood, although more research is needed to say it's a strong link. It's hard for our bodies to fully use magnesium when taken by mouth, but topical treatments such as salts dissolved in baths can be a valuable source of magnesium. If nothing else, a lovely relaxing bath may be just the ticket to help you unwind and get a good night's sleep.

Vitamin C is essential for a healthy immune system, working as an anti-oxidant to fight infection and inflammation and helping us absorb iron from food sources. It also stimulates collagen to help maintain strong bones and build firm, elastic skin and healthy hair. It's abundant in the summer, with fresh fruit and vegetables like berries, citrus fruits, peppers, potatoes, and leafy green vegetables all readily available. But we can't store it, so some turn to supplements in the winter to maintain levels.

Zinc: Known as a trace element as you only need a tiny amount, this is needed to support cells to build good immunity, prevent cold symptoms, and it helps regulate blood sugar levels by processing carbohydrates, fat, and protein from food. It's found naturally in red meat, cheese, shellfish, and bread.

Iron: Various factors mean that winter may cause a dip in iron levels, which can affect your health if you are already mildly anemic for other reasons. Many sources of iron come from the leafy green vegetables of summer, which vegetarians and vegans will be especially reliant on as they can't source their iron from red meat or dairy. In addition, vitamin C gives a helping hand to absorbing iron, and natural sources of this are in short supply in winter. So, it may be worth topping up iron levels with a supplement, especially if you know you are vulnerable, such as excluding certain food groups, pregnant women, or having heavy menstruation.

A lightbox: If you're missing the sunshine and think you might suffer from SAD, a light box can make all the difference. This aims to mimic the effect of sunlight, delivering an ambient, warm light. It's recommended to spend 30 to 60 minutes of exposure a day; it's all that's needed to boost your serotonin levels and counter the effects of melatonin, helping to make you feel more balanced.

Sleep patterns: While winter brings many reasons to sleep in for longer, try to resist this temptation and maintain a constant sleep-wake routine. This makes it easier to transition between seasons and helps maintain good energy levels, a balanced mood, and a consistent appetite.

Melatonin supplements: If insomnia creeps in, there are many ways to address this: good sleep hygiene, a daytime exercise routine, and mealtimes. Many wonders if melatonin supplements are the answer to help a night of restful sleep. Check with your doctor or pharmacist, as melatonin can interact with other medications.

Outdoor exercise: Regular exercise is a good way to keep energy levels pumped through winter, with added benefits to mood, eating, and sleeping routines. A healthy fit body also helps keep you and your airways in prime condition to fight off coughs and colds. If you can manage your workout outside, you also get a nourishing dose of fresh air and sunshine your body craves.

Mental health: Our urge to hunker down and stay warm and dry inside coincides with great TV scheduling and new releases, and maybe carb-heavy comfort food to boot. But it's also important to find the motivation to nurture your mental health. You may know what works for you, but many people find daily meditation, mindfulness, yoga, or even a walk in the park, noticing the season's changes, gives them a boost of energy and a feeling of balance and wellness in the gloom of winter. Planning events and having things to look forward to can also keep our spirits up, even if it's not quite the Caribbean holiday we would love.

When should I see my doctor?

We recommend getting the flu and COVID-19 vaccines – these usually get offered in the early autumn. They are considered very safe and effective in protecting you from the respiratory illness these viruses can cause. This is especially important for people of certain ages or with certain medical conditions. These vaccines are available at local pharmacies.

If you have a fever, you're coughing up thick green sputum, and you're finding breathing difficult, this could be bacterial pneumonia that requires antibiotic treatment. You are at higher risk of severe disease if you have asthma, COPD, smoking, or other long-term medical conditions, or if you are over 65, and you should seek urgent help from your doctor or the Emergency Department if after hours.

If you have reason to believe you may be low in specific vitamins or minerals – you are finding exercise much harder than usual, like being out of breath climbing a flight of stairs, if people say you look very pale, if you feel excessively fatigued or are sleeping much more than usual, or if your appetite or weight has changed – you should visit your doctor to discuss this. They will ask about symptoms and can send you for blood tests to check for anemia, reduced iron, vitamin D or B vitamins, and they can check your thyroid function – these may be related to winter, or they may be coincidental.

If you're feeling depressed and this is affecting your work life, studies, or personal relationships, and it hasn't shifted with simple lifestyle measures over several weeks, this may be caused to book an appointment with your doctor and talk through symptoms, signs, and options going forward. They may suggest a psychological intervention, such as cognitive behavioral therapy (CBT), or certain medications, such as anti-depressants.

If you have thoughts of harming yourself or suicide, you must seek help as soon as possible. You can tell a trusted friend or relative. Still, you should also access professional services, such as an urgent appointment with your doctor, a mental health Crisis Team if you're already known to them, or the Emergency Department if after hours.

Was this helpful?

Was this helpful?

Newsletter icon
Subscribe to our Newsletter
to get monthly notified about our latest health and wellness topics.
By clicking Subscribe, I agree to the Caidr Terms & Conditions and Privacy Policy and understand that I may opt out of the newsletter subscription at any time.