Worth knowing: health knowledge from Viterna

By Andreas | Viterna.at  ·  Last updated: 5 November 2026

Welcome to our knowledge page. This is where we collect everything we have learned in more than ten years of selling nutritional supplements and pass on to our customers every day: explained in plain language, without jargon and without miracle promises. Each guide answers the questions we are asked most often, names the claims that are officially authorised in the EU and shows at the end which product form suits which daily routine. The best place to start is the topic that is on your mind right now.

Our topic worlds

The in-depth guides from our newsletter. A new topic is added every two weeks.

Hands holding a glass flask of deep red algae culture in the sunlight of a greenhouse

Astaxanthin

Astaxanthin: what the red alga is and how much you get

The colour of salmon starts with an alga. Where astaxanthin comes from, how much is where and what amount the EU sets.

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Matching products: BiuAstin in the shop

A barefoot boy stands at a chalkboard wall with a chalk giraffe while an adult hand marks his height

Children

What children need to grow up healthy

What children are missing today, which nutrients matter at each age and what vitamin D, calcium, iodine and iron contribute to growth.

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Matching products: Children in the shop

Older hands lacing up a hiking boot on a wooden bench in autumn

Joints & bones

Joints, cartilage, movement: which nutrients really matter

Cartilage has no blood vessels and lives on movement. What vitamin C contributes, what collagen, glucosamine and MSM can do and which supplement suits you.

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Matching products: Joints & bones in the shop

A woman with long brown hair smiles by a window as she tucks a strand behind her ear

Hair, skin & nails

Hair vitamins: which nutrients really matter

Around 100,000 hairs, roughly 1 cm of growth a month. What biotin, zinc and selenium contribute, what millet and bamboo can do and which hair complex suits you.

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Matching products: Hair in the shop

An older man and a younger woman playing chess on a wooden board

Brain & mental fitness

Memory and mental fitness: what your brain really needs

Your brain makes up 2% of your body weight but uses 20% of its energy. The four building blocks of mental fitness and the nutrients that belong to them.

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Matching products: Omega-3 in the shop

Breakfast bowl with yoghurt, berries and oats on a kitchen table

Gut & immune system

Strengthen your immune system: why your defences start in the gut

Around 70% of your immune cells live in your gut. How to rebuild your gut flora in 8 weeks and what probiotics contribute.

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Matching products: Probiotics in the shop

A woman walks briskly along a tree-lined avenue in warm autumn morning light

Energy & iron

Tired all the time? Low iron could be the reason

What the ferritin value tells you, how to spot a deficiency and how the orange juice trick helps iron actually get absorbed.

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Matching products: Iron in the shop

Glass of water and muesli bowl on a kitchen table in morning light

Sport & creatine

Creatine: what it really does in your body

90% of your creatine is stored in your muscles. Why 3 g a day is enough, what it offers from age 55 and the 3 rules that really matter.

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Matching products: Sports nutrition in the shop

Grape harvest: hands picking ripe dark grapes in a vineyard

Cell protection & OPC

OPC grape seed extract: facts, intake and quality

What is behind the grape seed classic, what research says, 3 myths fact-checked and how to recognise good quality.

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Matching products: OPC by Optiolex

More guides

Popular posts from our blog, which we are revising step by step.

See all posts in chronological order

New knowledge every two weeks

Every new guide appears first in our newsletter: one topic, clearly explained, with the claims that are actually authorised. No constant advertising, unsubscribe at any time.

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Note: Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle. The content of this page is for general information and does not replace medical advice.