Nails and zinc deficiency are closely linked, as zinc plays a vital role in nail growth and structure. This essential trace element supports keratin production and cell division in the nail matrix, the tissue responsible for generating new nail. When zinc levels fall below optimal ranges, visible nail changes may develop, including horizontal grooves (Beau's lines), white spots, brittleness, and slow growth. Whilst these abnormalities can indicate zinc insufficiency, they may also result from other nutritional deficiencies, fungal infections, or systemic conditions. Understanding the relationship between zinc status and nail health enables early recognition of potential deficiency and guides appropriate assessment and management.

How Zinc Deficiency Affects Your Nails

Zinc is an essential trace element that plays a crucial role in numerous physiological processes throughout the body, including protein synthesis, cell division, and tissue repair. The nails, composed primarily of keratin—a structural protein—require adequate zinc levels for normal growth and maintenance. When zinc deficiency occurs, the rapid cell turnover in the nail matrix (the tissue beneath the base of the nail responsible for nail production) becomes compromised, leading to visible structural and cosmetic changes.

The mechanism by which zinc deficiency affects nail health is multifaceted. Zinc serves as a cofactor for over 300 enzymes involved in DNA synthesis and cellular proliferation. In the nail matrix, where cells divide rapidly to produce the nail plate, insufficient zinc impairs this process, resulting in slower nail growth and weakened nail structure. Additionally, zinc plays a vital role in collagen synthesis and immune function, both of which contribute to the integrity of the nail bed and surrounding tissues.

Key functions of zinc in nail health include:

• Supporting keratin production and structural protein formation

• Facilitating cell division in the nail matrix

• Maintaining the integrity of the nail bed

• Supporting immune function to prevent nail infections

When zinc levels fall below optimal ranges, these processes become disrupted, manifesting in nail changes. However, it's important to note that these nail changes are non-specific and can also result from other conditions including trauma, fungal infections, psoriasis, or other nutritional deficiencies. If you notice persistent nail abnormalities, consult your GP for proper assessment, as they may represent one sign of systemic zinc insufficiency or an entirely different condition.

Recognising Nail Changes Linked to Low Zinc Levels

Several nail abnormalities have been associated with zinc deficiency, though it is important to emphasise that these changes are not exclusively caused by low zinc and may indicate other nutritional deficiencies or dermatological conditions. The most commonly reported nail manifestation is the presence of Beau's lines—horizontal grooves or indentations that run across the nail plate. These transverse ridges develop when nail growth is temporarily disrupted at the matrix level, creating a visible depression that moves distally as the nail grows.

Another finding is leukonychia, presenting as white spots or streaks on the nail surface. Whilst leukonychia is most commonly the result of minor trauma to the nail matrix, persistent or widespread white discolouration may suggest nutritional deficiency, including inadequate zinc intake. Patients with compromised immune function, which can occur with zinc deficiency, may be more susceptible to nail infections, though paronychia (inflammation of the skin around the nail) is typically caused by local infection or trauma rather than zinc deficiency alone.

Additional nail changes that may be observed include:

• Brittle, fragile nails that split or break easily

• Slow nail growth

• Onycholysis (separation of the nail from the nail bed)—though this is more commonly associated with psoriasis, thyroid disease or fungal infection

• Rough, ridged nail surfaces

• Discolouration or dullness of the nail plate

These nail changes typically develop gradually and may be accompanied by other symptoms of zinc deficiency, such as hair loss, skin lesions, impaired wound healing, altered taste sensation, and immune dysfunction. Seek urgent medical attention if you develop severe painful swelling around the nail with pus or spreading redness, as this may indicate an infection requiring prompt treatment. For persistent nail abnormalities, particularly in combination with other symptoms, consult your GP for appropriate assessment.

Causes and Risk Factors for Zinc Deficiency

Zinc deficiency can arise from inadequate dietary intake, impaired absorption, increased losses, or elevated physiological requirements. In the United Kingdom, whilst severe zinc deficiency is relatively uncommon, mild to moderate deficiency may affect certain population groups. The recommended daily intake for adults is 9.5 mg for men and 7 mg for women, according to UK Dietary Reference Values, with requirements remaining the same during pregnancy and slightly increasing during lactation.

Dietary factors represent a primary cause of zinc deficiency. Zinc is predominantly found in animal-based foods such as red meat, poultry, seafood (particularly oysters), dairy products, and eggs. Individuals following vegetarian or vegan diets may be at increased risk, as plant-based zinc sources (legumes, nuts, seeds, whole grains) contain phytates that bind zinc and reduce its bioavailability. Restrictive eating patterns, food insecurity, or limited dietary variety can also contribute to insufficient zinc intake.

Malabsorption conditions significantly increase the risk of zinc deficiency. Gastrointestinal disorders such as Crohn's disease, ulcerative colitis, coeliac disease, and short bowel syndrome impair zinc absorption in the small intestine. Chronic diarrhoea from any cause results in excessive zinc losses. Additionally, individuals who have undergone bariatric surgery may experience reduced zinc absorption due to anatomical changes.

Other risk factors include:

• Chronic liver disease or chronic kidney disease

• Alcohol use disorder (impairs absorption and increases urinary losses)

• Lactation (slightly increased physiological requirements)

• Elderly individuals (reduced intake and absorption)

• Certain medications, including thiazide diuretics

• Genetic conditions such as acrodermatitis enteropathica (rare inherited disorder affecting zinc absorption)

Recognising these risk factors enables healthcare professionals to identify patients who may benefit from screening and allows individuals to assess their own potential vulnerability to zinc deficiency.

Diagnosing Zinc Deficiency Through Nail Symptoms

Whilst nail changes can provide valuable clinical clues suggesting zinc deficiency, diagnosis requires a comprehensive approach combining clinical assessment, dietary history, and biochemical testing. Nail symptoms alone are insufficient for definitive diagnosis, as numerous conditions—including other nutritional deficiencies (iron, biotin, protein), fungal infections, psoriasis, and systemic diseases—can produce similar nail abnormalities.

When a patient presents with nail changes suggestive of zinc deficiency, the GP will typically conduct a thorough clinical examination and detailed history. This includes assessment of dietary intake patterns, evaluation of gastrointestinal symptoms, review of medications, and identification of risk factors for malabsorption. The clinician will also look for other clinical features of zinc deficiency, such as characteristic skin lesions (particularly around body orifices), alopecia, impaired wound healing, altered taste or smell, and recurrent infections.

Laboratory investigation forms the cornerstone of diagnosis, though interpreting zinc status can be challenging. Serum or plasma zinc concentration is the most commonly used biomarker, with levels below approximately 10-12 μmol/L generally considered deficient in adults, though reference ranges vary between laboratories. Morning fasting samples are preferred, as food intake can temporarily lower serum zinc levels. Serum zinc has limitations: it represents only a small fraction of total body zinc, can be affected by acute inflammation (as zinc is a negative acute-phase reactant), and may not accurately reflect tissue zinc status in all cases.

According to UK guidance, additional investigations may include:

• Full blood count (to exclude anaemia)

• Inflammatory markers (CRP, ESR) to interpret zinc levels in context

• Assessment of other nutritional parameters (ferritin, vitamin B12, folate)

• Liver and kidney function tests

• Coeliac serology if malabsorption is suspected (as per NICE guidance)

In cases where clinical suspicion remains high despite normal serum zinc levels, or when there is evidence of malabsorption, referral to a specialist (gastroenterologist and/or registered dietitian) may be appropriate for further evaluation and management.

Treatment Options and Zinc Supplementation

The management of zinc deficiency involves addressing the underlying cause whilst providing zinc repletion through dietary modification or supplementation. Treatment should be individualised based on the severity of deficiency, presence of symptoms, underlying conditions, and patient-specific factors.

Dietary optimisation represents the first-line approach for mild deficiency or prevention. Patients should be advised to increase consumption of zinc-rich foods, with particular emphasis on bioavailable sources. Red meat, poultry, and seafood provide highly absorbable zinc. For those following plant-based diets, combining zinc-rich foods (legumes, nuts, seeds, fortified cereals) with strategies to reduce phytate content—such as soaking, sprouting, or fermenting—can enhance absorption. Registered dietitians can provide tailored dietary advice to ensure adequate zinc intake whilst respecting dietary preferences and restrictions.

Zinc supplementation is indicated when dietary measures are insufficient or when there is documented deficiency requiring more rapid correction. Various zinc formulations are available, including zinc sulphate, zinc gluconate, and zinc acetate. The typical supplementation dose for treating deficiency in adults ranges from 25 to 50 mg of elemental zinc daily, though higher doses may be required in severe deficiency or malabsorption states. It is important to check the elemental zinc content on product labels; for example, zinc sulphate monohydrate 125 mg contains approximately 45 mg of elemental zinc.

Important considerations for zinc supplementation:

• Take zinc supplements with food to reduce gastrointestinal side effects (nausea, abdominal discomfort)

• Avoid taking zinc simultaneously with iron supplements or calcium, as these can interfere with absorption

• Separate zinc from tetracycline or quinolone antibiotics by at least 2-3 hours

• Avoid long-term supplementation above 25 mg daily without medical supervision, as this may cause copper deficiency and should be monitored

• Duration of treatment typically ranges from 3 to 6 months, with reassessment of zinc status thereafter

For patients with underlying malabsorption conditions, treatment of the primary disorder (such as optimising inflammatory bowel disease management or adhering to a gluten-free diet in coeliac disease) is essential for long-term zinc status maintenance. In rare cases of severe deficiency or genetic disorders affecting zinc absorption, parenteral zinc therapy may be required under specialist supervision as part of a comprehensive trace element regimen.

If you experience side effects from zinc supplements, report them to the MHRA Yellow Card scheme.

Preventing Zinc Deficiency for Healthy Nails

Prevention of zinc deficiency centres on maintaining adequate dietary intake and addressing modifiable risk factors. For most individuals in the UK, a balanced diet containing varied food sources provides sufficient zinc to meet physiological requirements and support optimal nail health.

Dietary strategies for zinc sufficiency include:

• Following the NHS Eatwell Guide, which recommends at least 2 portions of fish per week (including 1 oily fish)

• Including beans, pulses, eggs and lean meat as part of a balanced diet

• Consuming dairy products, nuts, seeds, and whole grains regularly

• For vegetarians and vegans: emphasising legumes, fortified cereals, pumpkin seeds, and cashews whilst employing preparation methods that enhance bioavailability (soaking, sprouting, fermenting)

• Ensuring adequate overall protein intake, as protein-rich foods typically contain zinc

Specific population groups require particular attention to zinc intake. Breastfeeding women should ensure adequate zinc consumption through diet or supplements containing zinc. Elderly individuals, who may have reduced appetite, limited dietary variety, or impaired absorption, should be encouraged to maintain protein-rich diets and may benefit from nutritional assessment. Those with chronic gastrointestinal conditions should work with their healthcare team to optimise disease management and consider regular monitoring of nutritional status.

When to seek medical advice:

• Persistent nail changes that do not improve with dietary modifications

• Nail abnormalities accompanied by other symptoms (skin lesions, hair loss, recurrent infections)

• Known risk factors for zinc deficiency (malabsorption disorders, restrictive diets)

• Before starting zinc supplements, particularly if taking other medications or having existing health conditions

• Urgent care (NHS 111 or A&E) for severe infection around the nail with spreading redness, pus, or systemic symptoms

Regular health reviews with your GP provide opportunities to discuss nutritional concerns and assess risk factors for deficiency. Whilst zinc supplementation is widely available over the counter, it is advisable to consult a healthcare professional before commencing supplementation, as excessive zinc intake can cause adverse effects including copper deficiency, impaired immune function, and gastrointestinal symptoms. A balanced, evidence-based approach to nutrition, combined with appropriate medical assessment when concerns arise, offers the best strategy for maintaining optimal zinc status and supporting healthy nail growth throughout life.

Frequently Asked Questions