Food supplements: how to choose the right ones for your needs
Pharmacy shelves are full of hundreds of food supplements, and advertising promises energy, immunity and well-being. How do you work out what you specifically need?
In this guide you will find out where to start, which supplements most often suit different situations and when it is better to have tests done first.
In brief. A supplement is most useful when you get too little of a particular nutrient. If you constantly feel tired, first find out the cause – a simple blood test is often enough.1 Supplements do not replace a varied diet.2
Before you start: 3 questions to ask yourself
- What might I be lacking? Think about your diet, age, time of year and lifestyle. For example, if you do not eat meat, you may lack vitamin B12, and in winter, vitamin D.
- Can I get this checked? A deficiency of some nutrients, such as iron, vitamin B12 or vitamin D, can be identified with a blood test. Then you will know what you really need and avoid unnecessary supplements.
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What am I already taking? Add up the composition of all the supplements and vitamin-fortified products you use, so that you do not get too much of the same nutrient.
Supplement guide by situation
| Situation | What to check first | What most often suits |
|---|---|---|
| Constant tiredness | Blood test: haemoglobin, ferritin, vitamin B12, thyroid1 | Only what the test shows you are lacking |
| Confirmed iron deficiency | A doctor chooses the dose and duration3 | Iron supplement |
| Autumn and winter, little time outdoors | Whether you get sunlight4 | Vitamin D |
| Vegetarian or vegan diet | Whether you consume animal products | Vitamin B12, vitamin D, iodine, algae-based omega-35 |
| Planning a pregnancy | Talk to your doctor | Folic acid (400 µg) at least a month before conception6 |
| You rarely eat fish | How many times a week you eat oily fish | Omega-3 (EPA and DHA) |
| After the age of 50 | Vitamin B12 and D levels7 | Vitamin D, vitamin B12 |
| You exercise regularly | Whether you get enough protein from food | Creatine, protein (if not enough from food)8 |
“I have no energy” – will a supplement help?
Some nutrients contribute to the reduction of tiredness and fatigue: iron, magnesium, vitamins B12, B6 and C, and folate.8 However, a supplement helps only when you are lacking them.
Example. If you are tired because of low ferritin, an iron supplement may help. If your tiredness is caused by short sleep, stress or your thyroid, iron will not help, and an excess of it may even be harmful.13
If tiredness lasts for several weeks, see a doctor. Tiredness is often caused not by a lack of vitamins but by sleep, stress or other health reasons.1
How to read the label
- The amount of the nutrient, not of the compound. For example, 2,000 mg of magnesium bisglycinate contains only about 200 mg of magnesium.
- % NRV shows what percentage of the daily reference value you get. On EU labels it is calculated according to EU values.9
- Serving size. Sometimes a serving of 2 or 3 capsules is stated, rather than a single capsule.
What not to combine and when to be careful
- More is not better. Many vitamins and minerals have a safe upper limit, for example 100 µg per day for vitamin D and 25 mg per day for zinc.10
- Add it up. Multivitamins and individual supplements often contain the same nutrients.
- Medicines. Some supplements interact with medicines, for example vitamin K with warfarin.11 If you take medicines, consult a pharmacist.
- “Natural” does not mean “safe”. Herbal supplements can also have side effects.
Selected most commonly needed supplements
Commercial information. The products listed here are available in our shop. This is not a ranking of effectiveness. Before buying, check the composition and instructions for use on the product page.
D1000 Daily Vitamin D Oral Spray - 15 ml - BetterYou
Oral spray with 25 µg (1,000 IU) of vitamin D3 per spray. Convenient in autumn and winter, when sunlight is not enough. Contains xylitol.12
Iron, 18mg - 120 vcaps - NOW Foods
Iron bisglycinate, 18 mg of iron per capsule, 1 capsule per day with meals. Suitable when an iron deficiency has been confirmed by a test.13
Liposomal Vitamin B12, Methylcobalamin 100mcg - 60 vegan capsules - Osavi
Vitamin B12 in the form of methylcobalamin, 100 µg per capsule, 1 capsule per day after a meal. Suitable for vegans and vegetarians.14
Magnesium Glycinate - 180 tablets - NOW Foods
Magnesium bisglycinate, 200 mg of magnesium in two tablets. One serving is enough to avoid exceeding 250 mg of magnesium from supplements per day.1015
Frequently asked questions
Is it worth taking a multivitamin “just in case”?
If you eat a varied diet, you get enough of most nutrients. Multivitamins come in handy when the diet is restricted, but it is more sensible to supplement only what you are really lacking.2
How long should supplements be taken?
It depends on the goal. Vitamin D is most often taken in the dark season of the year, and iron until tests show that your stores have been restored.34
Where can I find more information about specific supplements?
We write about them in more detail in the articles Magnesium, Zinc and Supplements for athletes.
Scientific sources
- NHS. Why am I tired all the time? nhs.uk
- Direktyva 2002/46/EB dėl valstybių narių įstatymų, susijusių su maisto papildais, suderinimo. EUR-Lex
- NHS. Iron deficiency anaemia. nhs.uk
- NHS. Vitamin D. nhs.uk
- NHS. The vegan diet. nhs.uk
- Komisijos reglamentas (ES) Nr. 1135/2014 dėl leidimo naudoti teiginį apie maisto produktų sveikatingumą, susijusį su ligos rizikos mažinimu (folio rūgštis). EUR-Lex
- NIH Office of Dietary Supplements. Vitamin B12 – Fact Sheet for Health Professionals. ods.od.nih.gov
- Komisijos reglamentas (ES) Nr. 432/2012, kuriuo nustatomas leidžiamų teiginių apie maisto produktų sveikatingumą sąrašas (konsoliduota redakcija). EUR-Lex
- Reglamentas (ES) Nr. 1169/2011 dėl informacijos apie maistą teikimo vartotojams, XIII priedas. EUR-Lex
- EFSA. Overview on tolerable upper intake levels as derived by the Scientific Committee on Food and the EFSA Panel on Dietetic Products, Nutrition and Allergies. efsa.europa.eu
- NIH Office of Dietary Supplements. Vitamin K – Fact Sheet for Health Professionals. ods.od.nih.gov
- BetterYou. D1000 Daily Vitamin D Oral Spray, 15 ml. Product label.
- NOW Foods. Iron, 18 mg, 120 capsules. Product label.
- Osavi. Liposomal Vitamin B12, Methylcobalamin 100 mcg, 60 capsules. Product label.
- NOW Foods. Magnesium Glycinate, 180 tablets. Product label.
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 illness or if you take medicines, consult a healthcare professional.
