Which Vitamins May You Lack in Autumn?
In autumn the days get shorter, we spend more time indoors, and many people feel tired. A question often arises: could I be lacking vitamins?
In this article you will find out which vitamin level really does drop in autumn, which deficiencies depend not on the season but on diet, and how to check.
In brief. In autumn, only the vitamin D level really changes, because the sun weakens.1 Vitamin B12 and iron deficiency do not depend on the time of year, but they often show up as the same tiredness. If tiredness lasts longer, it is better to have a blood test than to choose supplements at random.
Vitamin D – falls along with the sun
Vitamin D is produced mainly in the skin under the influence of sunlight. From October to early March, in a large part of Europe the sun is too weak for the skin to produce enough of it.1 Stores built up in summer slowly run down in autumn.
Vitamin D contributes to the maintenance of normal bones, to the maintenance of normal muscle function and to the normal function of the immune system.2 For adults, about 15 µg (600 IU) per day is sufficient.3
Example. If you work in an office and are hardly ever outdoors during sunny hours, it is worth starting a vitamin D supplement as early as October rather than waiting for winter.
Vitamin B12 – diet matters, not the season
Vitamin B12 occurs naturally only in foods of animal origin: meat, fish, eggs and dairy products.4 Adults need about 4 µg per day.5
Vitamin B12 contributes to the reduction of tiredness and fatigue, to the normal function of the nervous system and to normal red blood cell formation.2
Deficiency is more common in:4
- vegans and some vegetarians;
- older people, because B12 is absorbed less well with age;
- people who take certain medicines for a long time, e.g. medicines that reduce stomach acidity or metformin.
Iron – deficiency is most common in women
Iron contributes to normal formation of haemoglobin and to the reduction of tiredness and fatigue.2 Premenopausal women need about 16 mg per day, men about 11 mg.6 Deficiency is more common with heavy periods, during pregnancy and when eating little meat.7
Take iron supplements only when a test confirms a deficiency. Too much iron is also harmful.7
What about vitamin C?
Vitamin C deficiency is rare in autumn. Apples, cabbage, peppers, pears and berries are easy to find. Adults need about 95–110 mg per day.8 You would get that, for example, by eating a pepper and an apple. A supplement is relevant only if you eat very little fruit and vegetables.
Tiredness in autumn: what to check?
| What you feel | Possible cause | What to do |
|---|---|---|
| Tiredness, little time outdoors | Vitamin D deficiency | Vitamin D from October to March. |
| Tiredness, tingling in the hands or feet, you do not eat animal products | Vitamin B12 deficiency | Blood test, B12 supplement for vegans. |
| Tiredness, shortness of breath, pale skin | Iron deficiency | Blood test (haemoglobin, ferritin). |
| Drowsiness, low mood | Less daylight, irregular sleep | A walk during the day, a consistent sleep routine. |
If tiredness or low mood lasts several weeks, see a doctor. Tiredness can be caused by more than a vitamin deficiency.
Selected products for autumn
Commercial information. The products listed here are available in our shop. This is not an effectiveness ranking. Before buying, check the composition and instructions for use on the product page.
Plant-Based Vitamin D3 Liquid, 1000 IU Apple - 30 ml - Nordic Naturals
Vitamin D3 from lichen, 25 µg (1000 IU) per 0.5 ml serving, apple flavour. Suitable for vegans. After opening, keep in the refrigerator and use within 3 months.9
Vitamin D3, 2000 IU - 120 softgels - Carlson Labs
Each capsule contains 50 µg (2000 IU) of vitamin D3; take 1 capsule per day with food. If you also take multivitamins, add up the amount of vitamin D.10
Liposomal Vitamin B12, Methylcobalamin 100mcg - 60 vegan capsules - Osavi
Vitamin B12 in the form of methylcobalamin, 100 µg per capsule; take 1 capsule per day after a meal. Gelatine-free capsules, suitable for vegans.11
Iron, 18mg - 120 vcaps - NOW Foods
Iron bisglycinate, 18 mg of iron per capsule; take 1 capsule per day with food. Suitable when an iron deficiency has been confirmed by a test.12
Frequently asked questions
Is it worth taking multivitamins in autumn?
If you eat a varied diet, vitamin D is usually enough. Multivitamins can be useful when your diet is restricted. Add up their composition with any other supplements you take.
Which tests should I have if I constantly feel tired?
The tests most commonly done are a complete blood count, ferritin, vitamin B12 and vitamin D. Your doctor will decide which tests to carry out.7
Is it possible to overdose on vitamin B12?
No safe upper limit has been established for vitamin B12, because a small excess is excreted in the urine.4 Nevertheless, take the dose specified by the manufacturer.
Scientific references
- NHS. Vitamin D. nhs.uk
- Komisijos reglamentas (ES) Nr. 432/2012, kuriuo nustatomas leidžiamų teiginių apie maisto produktų sveikatingumą sąrašas (konsoliduota redakcija). EUR-Lex
- EFSA NDA Panel. Dietary reference values for vitamin D. EFSA Journal. 2016;14(10):4547. doi:10.2903/j.efsa.2016.4547
- NIH Office of Dietary Supplements. Vitamin B12 – Fact Sheet for Health Professionals. ods.od.nih.gov
- EFSA NDA Panel. Scientific opinion on dietary reference values for cobalamin (vitamin B12). EFSA Journal. 2015;13(7):4150. doi:10.2903/j.efsa.2015.4150
- EFSA NDA Panel. Scientific opinion on dietary reference values for iron. EFSA Journal. 2015;13(10):4254. doi:10.2903/j.efsa.2015.4254
- NHS. Iron deficiency anaemia. nhs.uk
- 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
- Nordic Naturals. Plant-Based Vitamin D3 Liquid, 1000 IU, 30 ml. Product label.
- Carlson Labs. Vitamin D3, 2000 IU, 120 capsules. Product label.
- Osavi. Liposomal Vitamin B12, Methylcobalamin 100 mcg, 60 capsules. Product label.
- NOW Foods. Iron, 18 mg, 120 capsules. Product label.
Disclaimer. This article is for information purposes only and does not replace consultation with a doctor or pharmacist. Food supplements are not intended to treat or prevent diseases and are not a substitute for 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.
