Immune Support: Vitamins and Minerals Guide
What is immune support?
The immune system is the body's complex defence system, consisting of cells, tissues, and organs that work together to protect the organism. The immune system is constantly active, and its normal function depends on several factors, including nutrition.
Certain vitamins and minerals participate in normal immune system processes. The European Food Safety Authority (EFSA) has approved specific health claims for vitamin C, vitamin D, and zinc in relation to the normal function of the immune system.
This guide covers the most common immune support ingredients, highlighting only those claims that are officially approved by EFSA.
Supported benefits (EFSA-approved claims only)
The following claims are authorised under Commission Regulation (EU) No 432/2012. The conditions under which each claim is valid are listed alongside.
Vitamin C
- Vitamin C contributes to the normal function of the immune system — valid when the product contains at least 12 mg of vitamin C (15% of the Nutrient Reference Value) per 100 g, 100 ml, or per serving
- Vitamin C contributes to the protection of cells from oxidative stress — same condition
Vitamin D
- Vitamin D contributes to the normal function of the immune system — valid when the product contains at least 0.75 micrograms of vitamin D (15% of the Nutrient Reference Value) per 100 g, 100 ml, or per serving
Zinc
- Zinc contributes to the normal function of the immune system — valid when the product contains at least 1.5 mg of zinc (15% of the Nutrient Reference Value) per 100 g, 100 ml, or per serving
- Zinc contributes to the protection of cells from oxidative stress — same condition
Important note: Claims such as "boosts immunity", "prevents colds", "fights infections", or "strengthens the immune system" are not permitted. These exceed the bounds of EFSA-approved wording.
Common ingredients
Vitamin C (ascorbic acid)
Vitamin C is a water-soluble vitamin that the body cannot synthesise or store, meaning it must be obtained from food or supplements daily. Vitamin C is abundant in fruits and vegetables, particularly citrus fruits, bell peppers, blackcurrants, and rosehips.
Vitamin C contributes to the normal function of the immune system and contributes to the protection of cells from oxidative stress (EFSA-approved claims).
Available in tablet, capsule, effervescent tablet, powder, and liquid form.
Vitamin D
Vitamin D is a fat-soluble vitamin that the body produces in the skin when exposed to sunlight (UVB rays). In northern climates, vitamin D synthesis in the skin is limited from October to March, when UVB radiation is too weak.
Vitamin D contributes to the normal function of the immune system (EFSA-approved claim).
Available in capsule, tablet, drop, and chewable tablet form. As a fat-soluble vitamin, it is better absorbed when taken with fat-containing food.
Zinc
Zinc is an essential trace element that the body cannot store, requiring regular intake. Zinc is found in meat, nuts, seeds, legumes, and whole grains.
Zinc contributes to the normal function of the immune system and contributes to the protection of cells from oxidative stress (EFSA-approved claims).
Available in tablet, capsule, and lozenge form.
Echinacea
Echinacea is a genus of plants native to North America. The most common species used in supplements are Echinacea purpurea and Echinacea angustifolia. Echinacea preparations are made from various parts of the plant — root, herb, and flowers.
There are no EFSA-approved health claims for echinacea. It is described here only factually as a common ingredient in herbal supplements.
Elderberry (Sambucus nigra)
Elderberry is a woody plant that grows naturally in Europe. Elderberries are used to make syrups, extracts, and supplements. The berries contain vitamin C, fibre, and anthocyanins (dark plant pigments).
There are no EFSA-approved health claims for elderberry as a supplement ingredient. It is described here only factually.
Propolis
Propolis is a resinous substance produced by honeybees, collected from tree buds and used to coat and protect the hive. Propolis contains flavonoids, phenols, and other plant-derived compounds.
There are no EFSA-approved health claims for propolis as a supplement ingredient. It is described here only factually.
Forms
Immune support supplements are available in various forms:
- Tablets — common for multivitamins and minerals
- Capsules — typically contain concentrated extract or powder
- Effervescent tablets — dissolve in water, popular for vitamin C
- Liquid form — syrups and drops, often elderberry-based
- Lozenges — chewable tablets, often containing zinc
- Powder — mixable into drinks, often multi-ingredient blends
How to take them
- Always follow the recommended daily serving stated on the label — do not exceed it
- Vitamin C is water-soluble and can be taken regardless of meals
- Take vitamin D with fat-containing food for better absorption
- Zinc is best taken with food to reduce potential digestive discomfort
- When taking multiple ingredients, check that the total dose for each ingredient does not exceed the Nutrient Reference Value unless otherwise indicated
Seasonal considerations: In the Estonian climate, where winters are long and dark, vitamin D supplementation may be particularly relevant from October to March, when UVB radiation is insufficient for skin synthesis of vitamin D.
Who uses immune supplements?
Immune support supplements may be of interest to:
- Residents of Estonia and other northern countries — long, dark winters mean less sunlight and therefore less natural vitamin D synthesis
- People who want to ensure adequate vitamin and mineral intake — especially if their diet is limited or one-sided
- During seasonal changes — autumn and winter bring changes in routine and environment
- Physically active individuals — intense training increases the body's nutrient demands
- Older adults — with age, nutrient absorption and vitamin D skin synthesis become less efficient
Who should exercise caution:
- People taking medication — some vitamins and minerals may affect how medications work
- People already taking multiple supplements — check total doses, especially for fat-soluble vitamins (vitamin D)
- Pregnant and breastfeeding women — consult a doctor before using supplements
Frequently Asked Questions
Which vitamins and minerals are linked to normal immune system function?
EFSA has approved health claims for vitamin C, vitamin D, and zinc in relation to the normal function of the immune system. These claims are valid when specific dosage conditions are met.
Can I take multiple immune support supplements at once?
Yes, but check total doses to ensure no single ingredient exceeds the recommended limit. Be particularly careful with fat-soluble vitamins (vitamin D), which the body stores.
Are echinacea and elderberry EFSA-approved?
No, there are currently no EFSA-approved health claims for echinacea or elderberry as supplement ingredients. They are herbal ingredients used in supplements, but no health claims may be made about them.
Why is vitamin D especially relevant in Estonia?
The body synthesises vitamin D in the skin under UVB radiation. At Estonian latitudes, UVB radiation from October to March is too weak for the body to produce sufficient vitamin D. Vitamin D contributes to the normal function of the immune system (EFSA-approved claim).
Does vitamin C prevent colds?
No, this claim is not permitted. The EFSA-approved claim is: "Vitamin C contributes to the normal function of the immune system." This does not mean that vitamin C prevents or cures illness.
Should immune support supplements only be taken in winter?
Normal immune system function is important year-round. Supplement use is a personal decision. Vitamin D supplementation may be particularly relevant during the dark winter months when natural skin synthesis is limited.
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