Dry Skin: Could You Be Lacking Zinc?

Zinc is a crucial micronutrient, found in small quantities within the human body, at less than 50 mg/kg. It is vital for the body's health due to its critical roles in growth and development, bone metabolism, the central nervous system, immune function, and wound healing, which is the focus of this article.

Zinc is a vital cofactor for the function of over 10% of proteins encoded by the human genome, representing no less than 3000 proteins and enzymes ! Zinc-dependent proteins play numerous indispensable roles within cells, such as transcriptional regulation, DNA repair, cell death, metabolic processing, regulation of the extracellular matrix (ECM), and antioxidant defence.

Zinc is particularly important for the skin. The skin contains a relatively high zinc content (about 5% of the body content), mainly associated within the epidermis (50-70 μg/g of dry weight). Due to its abundance in the epidermis, it is observed that a zinc deficiency results in rough skin and an impaired barrier function. The skin becomes increasingly dry. Moreover, an alteration in wound healing is also correlated with this dietary deficiency.

If you are suffering from a zinc deficiency that is resulting in intense skin dryness, it may be beneficial to take zinc supplements, but always under medical advice. The maximum tolerable intake, defined as the highest daily dose that is unlikely to have adverse health effects, is 40 mg of zinc. Nausea, vomiting, diarrhoea, headaches, and cramps are some of the symptoms of zinc toxicity, beyond this 40 mg limit.

Furthermore, certain cosmetic active ingredients derived from zinc have moisturising properties for the skin when applied topically, such as zinc PCA.

Atopic dermatitis, more commonly known aseczema, is characterised by extreme skin dryness. Zinc has anti-inflammatory properties and enhances re-epithelialisation, supporting its use in the treatment of eczemas. Zinc oxide has long been used for the treatment of diaper dermatitis. Although this compound is less effective than other treatments such as topical corticosteroids, it is a useful soothing and anti-itch agent. A statistically significant improvement was observed with a cream containing zinc sulphate (2.5%) and clobetasol (0.05%) compared to a simple clobetasol-based cream (0.05%) in 47 patients suffering from chronic hand eczema in a prospective double-blind clinical trial. Topical zinc oxide, due to its strong antioxidant and antibacterial action, has also been used in the treatment of atopic dermatitis, a chronic inflammatory eczematous dermatosis characterised by an alteration of the skin barrier function, increased oxidative cellular stress and bacterial colonisation. Textiles impregnated with zinc oxide were tested in vivo for the management of atopic dermatitis in a study and a significant improvement was observed in disease severity, itching and subjective sleep in patients who wore zinc oxide-impregnated textiles compared to the control group. These zinc oxide-functionalised textiles could potentially be a future treatment modality of choice for atopic dermatitis.