Which Vitamins Should You Choose in Winter?
In winter the days are short, there is little sunshine, and more people around you have colds. That is why many people look for winter vitamins. However, the supplement shelf is long, and only a few are really needed.
In this article you will learn which vitamin matters most in winter, what vitamin C and zinc actually do, and how not to overdo it when combining several supplements.
In brief. In winter, vitamin D is the one most often lacking, because the sun is too weak.1 Vitamin C and zinc contribute to the normal function of the immune system, but with a varied diet you usually get enough of them.2 No supplement guarantees that you will not get ill.
Vitamin D – the most important in winter
Vitamin D is produced in the skin when it is exposed to sunlight. From October to early March, the sun is too weak in much of Europe, so vitamin D needs to come from food or supplements.1 It is hard to get from food: it is found mainly in oily fish and egg yolk.
Vitamin D contributes to the normal function of the immune system, to the maintenance of normal bones and to the maintenance of normal muscle function.2 For adults, about 15 µg (600 IU) per day is sufficient, and the upper safe limit is 100 µg (4000 IU).34
Example. A drop containing 25 µg (1000 IU) of vitamin D3 daily is a convenient and safe choice for most adults during the winter months.
Vitamin C – does it protect against colds?
Vitamin C contributes to the normal function of the immune system and to the reduction of tiredness and fatigue.2 However, you should not expect miracles from it.
In a review covering 29 studies with more than 11,000 participants, vitamin C taken daily did not reduce the number of colds. In adults, a cold lasted on average about 8% less time.5 When vitamin C was started after people had already become ill, no clear benefit was observed.5
Adults need about 95–110 mg of vitamin C per day.6 You will get that from, for example, an orange and a red pepper. A supplement can be useful if you eat few fruits and vegetables.
Zinc – in small doses
Zinc contributes to the normal function of the immune system.2 It is found in meat, seafood, cheese, legumes and wholegrain products. Adults need roughly 7–16 mg per day, depending on sex and diet.7
The upper safe limit is 25 mg per day from all sources.8 Taking more over a long period may lead to copper deficiency.8
Do you need all of them at once?
| Situation | Which supplements are worth considering |
|---|---|
| What most adults need in winter | Vitamin D. |
| You eat few fruits and vegetables | Vitamin C or multivitamins. |
| You eat little meat or are vegetarian | Zinc (at a lower dose). |
| You eat a varied diet and are often outdoors | You may not need supplements, except vitamin D. |
Add up the amounts. If you take multivitamins, a vitamin C and zinc combination and a separate zinc supplement, add up the amounts of zinc and vitamin D in all the products. For example, 15 mg + 15 mg of zinc already exceeds the 25 mg limit.
Supplements do not replace sleep, physical activity and a varied diet. Also wash your hands often – it is a simple way to reduce the risk of catching a cold.9
Selected winter vitamins
Commercial information. The products listed here are available in our shop. This is not an effectiveness ranking. Before buying, check the ingredients and directions for use on the product page.
Vitamin D-3 Liquid, 1000 IU (Extra Strength) - 30 ml - NOW Foods
Vitamin D3 drops, 25 µg (1000 IU) per drop. The manufacturer states 1 drop 1–2 times per day. The vitamin D3 is derived from lanolin, so it is not suitable for vegans.10
Vitamin C with Bioflavonoids - Vitamin C - 500 mg - 90 capsules - Swanson
Each capsule contains 500 mg of vitamin C and 100 mg of citrus bioflavonoids. Take 1 capsule per day with a meal. The capsule contains gelatin.11
Mineral Zinc 100% Chelate, 15mg - 100 vcaps - Nutrend
Zinc bisglycinate, 15 mg of zinc per capsule, no more than 1 capsule per day. If you take multivitamins containing zinc, add up the amounts.12
C-1000 Zinc Immune - 180 vcaps - NOW Foods
Each capsule contains 1000 mg of vitamin C and 15 mg of zinc (as bisglycinate). Take 1 capsule per day with a meal. Do not take it together with a separate zinc supplement, so that you do not exceed 25 mg of zinc.13
Frequently asked questions
When should I start taking vitamin D?
It is most convenient to start in October and continue until the end of March.1 If you are rarely outdoors or always keep your skin covered, you may need vitamin D all year round.
Will a high dose of vitamin C help me recover faster?
When vitamin C was started after people had already become ill, no clear benefit was found in studies.5 Very high doses of several grams may cause diarrhoea and stomach discomfort.14
Is it worth taking probiotics in winter?
Study results are inconsistent and depend on the specific bacterial strains. Read more about this in the article Probiotics and good bacteria.
Scientific sources
- NHS. Vitamin D. nhs.uk
- Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods (consolidated version). EUR-Lex
- EFSA NDA Panel. Dietary reference values for vitamin D. EFSA Journal. 2016;14(10):4547. doi:10.2903/j.efsa.2016.4547
- EFSA NDA Panel. Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate. EFSA Journal. 2023;21(8):8145. doi:10.2903/j.efsa.2023.8145
- Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;(1):CD000980. doi:10.1002/14651858.CD000980.pub4
- EFSA NDA Panel. Scientific opinion on dietary reference values for vitamin C. EFSA Journal. 2013;11(11):3418. doi:10.2903/j.efsa.2013.3418
- EFSA NDA Panel. Scientific opinion on dietary reference values for zinc. EFSA Journal. 2014;12(10):3844. doi:10.2903/j.efsa.2014.3844
- Scientific Committee on Food, EFSA. Tolerable upper intake levels for vitamins and minerals. 2006. efsa.europa.eu
- World Health Organization (WHO). Hand hygiene: why, how and when? who.int
- NOW Foods. Vitamin D-3 Liquid, 1000 IU, 30 ml. Product label.
- Swanson. Vitamin C with Bioflavonoids, 500 mg, 90 capsules. Product label.
- Nutrend. Mineral Zinc 100% Chelate, 15 mg, 100 capsules. Product label.
- NOW Foods. C-1000 Zinc Immune, 180 capsules. Product label.
- NIH Office of Dietary Supplements. Vitamin C – Fact Sheet for Health Professionals. ods.od.nih.gov
Disclaimer. This article is for information purposes only and does not replace a consultation with a doctor or pharmacist. Food supplements are not intended to treat or prevent diseases and do not replace a varied diet and a healthy lifestyle. Before taking supplements, especially during pregnancy or breastfeeding, if you have a chronic condition or if you are taking medicines, consult a healthcare professional.
