Zinc Deficiency

Zinc Deficiency

What is Zinc? 

Zinc is an essential trace metal required for cell growth & repair, immune function, gastrointestinal function, neurologic function, and many other important biochemical functions in the body. Zinc deficiency results in impaired antioxidant defenses and negative effects on many important proteins and enzymes.
There are more than 100 zinc-dependent enzymes in the body and are found in every organ system. As part of the biochemical machinery of the brain, zinc is involved in production of neurotransmitters, especially GABA. This is the catalytic role of zinc in biological systems. Zinc also serves to provide structure to proteins and cell membranes, thereby protecting them from oxidative stress and impaired function.
In addition to the catalytic and structural roles of zinc, in the form of zinc finger proteins it is involved in gene expression by acting as transcription factors, which turn on or off expression of our DNA. This influence can alter cell signaling and thereby influence release of hormones or in other cases transmission of a nerve signal along the cell.
The role of zinc in protection from oxidative stress should not be underestimated. Zinc ingestion is a potent inducer of metallothionein, a family of proteins involved in copper metabolism, zinc transport, recycling of reduced and functional form glutathione (the currency of antioxidant action in the body), protection from heavy metal toxicity, and pruning during development and learning.

What are the symptoms of Zinc Deficiency?

Because of the many effects of zinc, deficiency signs and symptoms can be quite diverse. White spots on the nails, psoriasis, acne, eczema, poor wound healing and hypogeusia (impaired sensitivity to taste) are related to the adverse effects on the dermal and immune systems. Decreased appetite, diarrhea, stunted growth, and delayed maturation are adverse effects on the endocrine and gastrointestinal system. Poor memory, irritability, and other behavioral disturbance are negative effects of zinc deficiency on brain function. Recurrent infections or increased susceptibility to unusual infections are negative effects on immune function
A high incidence of zinc deficiency is found in patients with ADHD, autism spectrum disorders, depression, schizophrenia, and bipolar disorder.

How is Zinc Deficiency Diagnosed?

Zinc deficiency is diagnosed by a finding a plasma zinc level below 100 mcg/dl. Plasma zinc is the most reliable measure of zinc adequacy and is preferred to serum zinc or intracellular zinc levels, which are less accurate.
The clinical sign of zinc deficiency is white spots on the nails.

How is Zinc Deficiency treated?

Zinc deficiency is corrected with supplementation of zinc intake. The severity of the deficiency, based on laboratory findings and clinical symptoms, determines the starting dose of zinc. The final dose is based upon ongoing measurement of plasma zinc to achieve a plasma level of 100-120 mcg/dl.
Zinc citrate is the most common form of zinc found in breast milk and is one of the preferred zinc salts to use for supplementation. Zinc picolinate is also well absorbed and is also used. Zinc arginate is potentially more absorbable in certain bowel diseases, because it is absorbed at the base and not the end of the intestinal villus (often shortened in bowel disease).  Zinc sulfate is useful dosing of zinc for dermal (skin) absorption; however, due to nausea is not well tolerated orally.  Because vitamin B6, vitamin C, vitamin E, and magnesium are often co-factors with zinc, they are also included as part of zinc deficiency treatment.
Zinc supplementation can lower copper levels; therefore, serum copper levels are also followed to ensure that supplementation of zinc has not adversely affected copper metabolism. Supplemental copper is rarely needed; however, is the solution when higher zinc doses are needed clinically, yet lead to low copper levels. In the case of concomitant abnormally high copper levels, supplementation with zinc needs to proceed gradually because zinc will induce copper elimination, which can induce irritability.

References:

Micronutrient Information Center at the Linus Pauling Institute.
Pfeiffer, CC.  Nutrition and Mental Illness.

Information from www.integrativepediatricsofohio.com