Zinc Requirement

Zinc is a little different from some of the other well-known minerals.  Whilst some of these have a well-known, identifiable function familiar to us, such as calcium for bone strength and iron for healthy red blood cells, zinc has no single clear action but instead performs a number of important functions in the body.  This is because zinc is an essential component of around 200 enzymes that are involved in a range of actions within the body. Zinc is needed for a healthy immune system as it is involved with immune cell (T-cell) production in the thymus gland.  Along with copper and manganese, zinc is a precursor of the antioxidant enzyme superoxide dismutase (SOD).  Zinc is needed for protein synthesis and is important in wound healing and growth.  It plays an important role in the repair and renewal of skin cells.

Zinc is an essential trace element.  It is one of the most important of the trace elements needed by the body.  Of the many hundreds of protein enzymes present in the body, which allow its chemistry to work, zinc is required by over two hundred of them.  It can thus be seen how a deficiency of zinc can affect so many different functions.

Zinc is also important in the production of prostaglandins (PGs).  PGs are vital to numerous body functions including, for example: the function of the immune system; the expression and control of inflammation; skin and wound healing; function of the heart and cardiovascular system; absorption of various minerals; body temperature control and the important functions of fertility, conception, and delivery of the infant.  The way in which zinc influences PG production is by potentiating (or supporting the function of) the enzymes which permit the conversion of the polyunsaturated fatty acids into PGs.  Zinc thus has a very direct action in stimulating the normal production of PGs thereby maintaining or restoring normal health and fitness.

Incidence; Causes and Development

Zinc deficiency occurs more frequently than is commonly recognized.  It tends to occur in the elderly, when zinc intake is inadequate, when there are increased losses of zinc from the body, when copper exposure is high, or when the body's requirement for zinc increases.

Gastrointestinal malabsorption can lead to deficiency.

Signs and Symptoms

There is no specific disease associated with zinc deficiency, but many general signs and symptoms can point to it.  As body stores of zinc decline, symptoms worsen and new ones appear.

Symptoms of deficiency include:

• mild anemia
• glossitis
• angular stomatitis
• diverse forms of skin lesions, including eczema, psoriasis, acne
• night blindness (poor night vision), associated with an inability to mobilize retinol from the liver, may also be caused by zinc deficiency
• photophobia (sensitivity to light)
• hang nails
• inflammation of nail cuticles
• white spots on fingernails, transverse lines and poor nail growth
• sleep and behavioral disturbances
• psychiatric illness
• all types of inflammatory bowel disease
• impaired glucose tolerance
• dandruff
• arthritis
• alcoholism
• loss of appetite
• growth retardation
• diarrhoea
• tremor
• hair loss
• dry skin rash
• increased allergic sensitivity
• disturbance of menstrual periods, pre-menstrual syndrome
• delayed wound healing
• loss of taste or smell sensation
• dyslexia
• depression
• sleep disturbance
• hyperactivity
• reduced fertility
• loss of sex drive
• pre-eclampsia (toxaemia) of pregnancy and post-natal depression

A diet marginally lacking in zinc can lead to problems such as:

• frequent infections
• delayed wound healing
• reduced appetite
• decreased sense of taste and smell (sometimes also associated with low iron levels)
• poor skin condition
• white flecks on the nails

A very severe zinc deficiency will lead to stunted growth (as related to protein metabolism) and delayed/poor sexual development.  Such drastically low levels of zinc are not generally seen in Western countries, but some groups - particularly young women between 16 and 24 - do often have lower than desirable intakes.

Some 25% of people who have an impairment in taste and or smell are suffering from an outright zinc deficiency.

Another common condition that can develop is Acrodermatitis Enteropathica, an autosomal recessive disease that is characterized by zinc malabsorption.  This results in eczematoid skin lesions, alopecia, diarrhea, and concurrent bacterial and yeast infections.

It has been observed that those suffering with any of the auto-immune diseases (such as multiple sclerosis, rheumatoid arthritis or psoriasis); atopic problems (allergy, eczema, asthma or migraine); or many of the inflammatory diseases (such as osteo-arthritis, ME or irritable bowel syndrome), have a consistent, and often severe, zinc deficiency, which is greatly benefited by a programme of zinc replacement therapy.  Zinc supplements in MS will increase both energy and vitality, increase muscle strength, improve sleep and prevent fatigue.  Perhaps in company with vanadium, another common mineral deficiency in MS, which contributes to the occurrence of depression, it will also prevent this distressing symptom.

Diagnosis and Tests

Medical doctors who suspect a zinc deficiency will consider risk factors such as inadequate caloric intake, alcoholism, digestive diseases, and symptoms such as impaired growth in infants and children when determining a need for zinc supplementation.

Treatment and Prevention

Even a marginal deficiency should not be left untreated.

Men have a high concentration of zinc in their prostate gland, and many anecdotal reports indicate that benign enlargement of the prostate gland - causing increased frequency of urination in middle aged men - can be improved by consuming extra zinc.

Zinc is commonly taken as a supplement to help with skin conditions such as acne or eczema.  The basis of zinc therapy lies in the fact that the mineral is necessary for normal cell division, tissue repair and renewal.  Zinc is also needed for the conversion of essential fatty acids into compounds that help regulate skin condition.

Complications

Studies at Reading University (UK) have shown that zinc deficiency contributes to the slimming disease anorexia nervosa by impairing the sense of taste and smell, and therefore the desire to eat.  Pioneering work at the university has used zinc as part of the treatment programmes for anorexia nervosa victims.

Zinc is also important for reproductive health.  Low zinc levels may result in reduced sperm count, and pregnant women with low blood levels of zinc may give birth to smaller babies.  Poor growth in the first few months of life has been associated with reduced levels of zinc in breast milk.