After iron, zinc is the most common mineral in the body. This mineral plays important roles in the functioning of more than 300 hormones and enzymes, and a deficiency in zinc may lead to various health problems.
People with zinc deficiency may experience symptoms, such as brittle nails, white spots on the fingernails, hair loss, fatigue, low sex drive, body odor, and adult acne. Here are the consequences of being zinc-deficient:
Zinc deficiency weakens the immune system – Zinc is responsible for activating and supporting T-lymphocytes, which target and destroy infected cells. A lack of zinc can reduce the body's supply of T-lymphocytes, leading to a weaker ability to fight infections and heal wounds. Zinc deficiency is also associated with many diseases and conditions, such as anemia, impaired growth in children, diarrhea and pneumonia in infants, and higher infant mortality. Zinc is also essential in supporting the thymus gland, a key component of the immune system. Zinc can help maintain the healthy function of the thymus gland in older adults. Research also shows that zinc boosts and supports immunity, thus a shortage of zinc can weaken the body's immune defenses. (Related: Zinc deficiency worsens sepsis, causes 'catastrophic malfunctioning' of immune system, increases inflammation.)
Zinc deficiency contributes to tumor growth – According to studies, zinc controls the production of the pro-inflammatory enzyme COX-2, which has been linked to the growth of certain cancers – particularly of the esophagus and tongue. Scientists also say that patients with these types of cancer are often lacking in zinc, at the same time, exhibiting elevated COX-2 levels. In animal studies, zinc deficiency has been shown to promote tumor growth and COX-2, and increasing zinc levels to optimal led to less COX-2 production and less incidence of tumors.
Zinc deficiency causes slowed growth, cognitive problems, and depression – Zinc is needed for normal growth and development, and is important to learning and memory. Thus a shortage of this mineral can cause cognitive problems and slowed growth. According to animal studies, even moderate zinc deficiency can hamper normal growth and maturation, while causing behavioral changes like lethargy. Zinc deficiency can also trigger changes in the hippocampus and prefrontal cortex of the brain. Animal studies revealed that diets low in zinc cause depression, poor motivation, and social withdrawal; while in human studies, lack of zinc is linked to impairments of normal bone mineralization, short stature, and developmental delays.
What to do about it?
Fortunately, some of these changes are reversible through zinc supplementation. A review of clinical trials noted that zinc supplementation resulted in highly significant and positive effects in height and weight. In fact, in one study, researchers discovered that supplementation of zinc enhanced the production of insulin-like growth factor and other proteins involved in bone development and overall growth. Zinc supplementation can also decrease the severity and duration of colds and respiratory infections. Zinc prevents viruses from clinging to respiratory tract cells and reproducing – which is important in preventing infections from taking hold and causing symptoms. Clinical studies with both children and adults confirm that zinc lozenges can relieve cold symptoms and the length of the illness if used within the first 24 hours of the development of symptoms.
Including zinc in your diet
Because the body does not store zinc, it is important to eat enough foods rich in zinc each day to meet the daily requirements and avoid deficiency. The recommended daily zinc requirement for men and pregnant women is 11 milligrams (mg); women need eight mg; and breastfeeding women need 12 mg.
Here are 10 best sources of zinc to include in your diet: