Nutrients for Strong Fingernails: Zinc & Selenium

The nail splits yet again while opening a bag, and beauty ads reflexively cry "Biotin!". Yet when it comes to fingernails, that claim is legally off the mark. Here is the surprising truth.

For strong fingernails, zinc and selenium are the right nutrients - both contribute to the maintenance of normal nails. Biotin, by contrast, only holds a health claim for hair and skin, not for nails. Because nails grow slowly, changes only show after weeks.

What fingernails are made of

Fingernails are made of keratin, a firm structural protein that is also found in hair and the outermost layer of skin. They form in the nail root beneath the skin and slowly push forward from there - around half a millimetre to a millimetre per week. A complete fingernail takes several months to grow through from the root to the tip. That is why patience is called for when it comes to nails: if you change your nutrient supply, you will not see effects within days, but only once the newly formed section of nail has grown out. Interesting: fingernails grow faster than toenails and usually somewhat quicker in summer than in winter - a sign of how many factors influence nail formation.

Zinc and selenium - the approved nail nutrients

Zinc is involved in many metabolic processes and in the formation of structural proteins - details in Zinc: Effects, Daily Requirement and Deficiency and on the best form in Zinc Bisglycinate vs. Gluconate. Selenium is a trace element that likewise contributes to the maintenance of normal nails - more in Selenium: Effects, Daily Requirement and Form.

Why not biotin? The subtle but important difference

Biotin (vitamin B7) is often marketed across the board with beautiful nails - but legally that is not clean. In the EU, biotin is only approved for the maintenance of normal hair and skin as well as for metabolic and nervous functions, not for nails. Health claims apply to specific bodily functions in each case and are not transferable across the board: a nutrient with a hair claim may not automatically be advertised for nails as well. As a reputable supplier, we adhere strictly to this - for nails, zinc and selenium are the correct reference points. How biotin, zinc and selenium interact in the beauty context is put into perspective by Skin, Hair, Nails: Biotin, Zinc and Selenium; what biotin is actually approved for is clarified by Biotin (Vitamin B7) for Skin and Hair.

What encourages brittle nails

Before you reach for supplements, it is worth taking an honest look at the most common everyday causes of soft or splitting nails - because often it is not down to diet at all:

• Water and cleaning agents: frequent hand washing, cleaning without gloves and dish soap draw moisture and oil out of the nail.
• Acetone nail polish remover: noticeably dries out the nail plate when used often.
• Mechanical strain: using nails as a tool or filing them too short and square weakens the structure.
• Dry heated air in winter: it too can dry out nails and cuticles.

Only once these factors are under control and the nails still remain noticeably affected is it worth looking at the nutrient supply - and then zinc and selenium are the right starting points.

Good food sources

Just a few Brazil nuts provide plenty of selenium - no large amount is needed here. With zinc the rule is: only when required and not permanently at high doses, since a sustained excess can affect the copper balance. Guidance on this is given by Zinc and Copper in Balance, and how long a zinc course makes sense is clarified by Zinc: Course or Continuous?.

What research is investigating

Around nails and nutrients, researchers investigate how the supply of trace elements and structural proteins affects the condition of keratin tissues. It is textbook-established that nails are made of keratin and that zinc and selenium are involved in processes that are important for their normal maintenance - and that is exactly what the approved statements refer to. Much else, such as the influence of individual nutrients on growth speed or hardness, is the subject of ongoing research and varies from person to person.

Protecting nails in everyday life

Nutrition from within, the right handling from without - both count:

• Wear gloves during housework and cleaning to protect nails from water and cleaning agents.
• Regularly care for nails and cuticles with a rich cream or an oil.
• Use acetone-based nail polish remover only sparingly - it dries them out.
• Do not cut or file nails too short or too square.
• Pay attention to a diet rich in protein and trace elements - keratin is made of protein.

Honestly put into perspective: myths about nails

• "White spots mean a calcium deficiency." Not proven that way - white spots usually arise from small mechanical impacts on the growing nail.
• "A supplement makes hard nails." Nails grow slowly, and their condition depends on many factors. A good overall supply is more sensible than a single miracle product.
• "More helps more." With zinc and selenium too, a needs-based intake is the goal - high doses over a long time are not advisable.

When to have nails checked medically?

Some nail changes can have other causes. With clearly discoloured, thickened, detaching or suddenly strongly changed nails, as well as with recurring inflammation of the nail bed, medical advice is part of it, rather than relying on supplements alone. Food supplements are no substitute for a medical assessment.

In practice: dosage, form and course duration

If you want to specifically supplement zinc or selenium, it comes down to amount and form:

• Zinc is best taken with some distance from meals very rich in calcium or iron, as these can affect absorption - more in Taking Zinc With or Without Food. Well-tolerated forms such as zinc bisglycinate are frequently recommended.
• Selenium is effective even in small amounts - a few Brazil nuts cover a lot. As a supplement, selenium from selenium yeast is a common form.
• Course or continuous? For nails, because of the slow growth, a period of several months makes sense so that the newly formed section of nail can grow out. Zinc, however, should not be taken at high doses on a permanent basis - orientation is given by Zinc: How Long to Take It?.

And because keratin is made of protein, an overall protein-rich diet is the quiet foundation of strong nails - a point that beauty advertising likes to gloss over.

Nails, skin and hair are connected

Nails, skin and hair are partly made of keratin and share several nutrients. That is why zinc and selenium also appear in guides on skin and hair - for instance in Nutrients for Hair and Nutrients for Healthy Hair Growth. A good basic supply therefore benefits several of these structures at once - one more argument for building on a solid foundation instead of relying on a single miracle product.

Matching products from Scheunengut

In the categories Zinc and Selenium you will find suitable single-nutrient supplements, such as zinc bisglycinate or selenium from selenium yeast. Bundled together, beauty nutrients are available in Beauty - Skin, Hair & Nails. All products are lab-tested and made in Germany.

Frequently Asked Questions (FAQ)

Which nutrients are good for strong fingernails?

For nails, zinc and selenium are the fitting nutrients - both contribute to the maintenance of normal nails. They are found in pumpkin seeds, cheese, legumes, Brazil nuts, fish and eggs. A needs-based supply is more sensible than high doses.

Does biotin help with brittle nails?

For nails, biotin is not approved in the EU - the health claim applies only to hair and skin. For strong nails, zinc and selenium are the correct reference points instead. Biotin can play a supporting role for hair and skin.

How long does it take for nails to improve?

Nails grow only about half a millimetre to a millimetre per week, and a complete fingernail takes several months to grow through. Effects of a changed nutrient supply therefore only show after weeks to months - patience is called for.

Do white spots on nails mean a deficiency?

Usually not. White spots generally arise from small mechanical impacts on the growing nail and are no reliable sign of a calcium deficiency. With strongly or suddenly changed nails, a medical assessment is advisable.