Zinc is a trace mineral that the body uses for a vast array of functions, from building proteins and creating new cells to supporting the immune system. It is involved in the action of numerous enzymes, which are proteins that facilitate chemical reactions for metabolism, growth, and development. The body does not produce or store zinc, meaning a consistent supply from the diet is necessary to maintain adequate levels and support these widespread physiological processes.
Signs and Symptoms of Zinc Deficiency
Low levels of zinc can manifest in various ways, affecting the skin, hair, and nails first. A common sign is the development of skin issues like rashes, acne, or eczema, and wounds may heal much more slowly than usual. Changes to hair can include thinning or general hair loss, as zinc is needed for hair follicle function. Fingernails may also show signs, such as becoming brittle, breaking easily, or developing white spots or lines.
The senses of taste and smell are also impacted by a lack of zinc. A reduced sense of taste or smell can be an early indicator of a deficiency. Some individuals may experience changes in their mouth, including a white coating on the tongue, recurrent mouth ulcers, or gum inflammation. These sensory changes can contribute to a loss of appetite, which complicates nutritional intake.
A deficiency can lead to increased susceptibility to infections, as a well-functioning immune system relies on adequate zinc. Getting sick often with colds or other illnesses could be related to insufficient zinc. Beyond immunity, low zinc can cause generalized symptoms like a lack of energy, irritability, and unexplained weight loss. In more severe cases, particularly in children and adolescents, it can lead to slower than expected growth and delayed puberty.
Causes and Risk Factors
The most direct cause of zinc deficiency is an insufficient intake of zinc-rich foods over an extended period. This is particularly common in individuals following vegetarian or vegan diets, as the zinc from plant-based foods is often less bioavailable, meaning the body absorbs it less easily than zinc from animal products.
Certain medical conditions can interfere with the body’s ability to absorb or retain zinc, leading to a deficiency. Gastrointestinal diseases such as Crohn’s disease, ulcerative colitis, and celiac disease can damage the intestinal lining and impair nutrient absorption. Chronic liver or kidney disease can also affect the body’s zinc regulation and increase losses of the mineral.
Specific life stages and conditions elevate the body’s demand for zinc, increasing the risk of a deficiency. Pregnant and breastfeeding women require more zinc to support the development of the fetus and produce milk. Infants, children, and adolescents also have higher needs for their rapid growth. People with alcoholism are another at-risk group, as alcohol can impair zinc absorption and increase its excretion through urine.
Diagnosing and Testing for Deficiency
Identifying a zinc deficiency involves a comprehensive evaluation by a healthcare provider. The process begins with a discussion of your diet, an assessment of your symptoms, and a review of your medical history to identify any potential risk factors.
A common method is a plasma or serum zinc test, which measures the amount of the mineral in your blood. However, these tests have limitations because blood levels may not accurately reflect the total amount of zinc stored in your body’s tissues. Blood concentrations can appear normal even when a mild or moderate deficiency exists.
A diagnosis is made by combining the test results with the clinical assessment of symptoms and risk factors. In some cases, a healthcare provider might suggest a trial of zinc supplementation to see if symptoms improve. This response to supplementation can serve as a functional confirmation of the deficiency.
Restoring Zinc Levels Through Diet and Supplementation
Increasing the intake of zinc-rich foods is a primary strategy for addressing low levels. Animal-based foods are excellent sources due to their high bioavailability. Oysters are particularly potent, containing more zinc per serving than any other food, followed by red meat like beef and lamb, and poultry such as chicken and turkey.
For those who follow plant-based diets, several options are available, though they contain compounds called phytates that can inhibit zinc absorption. Good plant-based sources include whole grains and the following:
- Beans, lentils, and chickpeas
- Nuts like cashews and almonds
- Seeds such as pumpkin and hemp
When dietary changes are insufficient or a deficiency is more significant, a healthcare provider may recommend supplementation. Zinc supplements are available in various forms, including zinc gluconate, zinc picolinate, and zinc citrate, with absorption rates varying between them. It is important to follow the prescribed dosage, as excessive zinc intake can be toxic. High doses can interfere with the absorption of other minerals, particularly copper, leading to a copper deficiency.