Zinc is one of our key minerals, with lots of different roles in the body. It is called an “essential” element, which means it is crucial to our survival. It is estimated that millions of people worldwide may be zinc deficient. In developing nations, this may cause life-threatening health conditions including unrelenting diarrhea that can render people susceptible to pathogens, but even in developed nations, zinc deficiency is more common than we think, and may contribute to more health problems than we think.
In children, zinc deficiency can cause serious issues by slowing normal growth and development, as well as delayed sexual maturation. For all ages, immune function is dependent on having adequate zinc – it is involved in T-cell production and function, and also in preventing excessive release of histamines (which manifest as allergy-type symptoms). Low zinc status usually makes one more susceptible to infections.
One of the big issues around zinc deficiency is impaired neurological function. It plays a role in attention and focus, which is such a profound issue for so many kids these days (and many of us adults too!). It is also implicated in depression and has been used successfully in some cases as a treatment for depression.
There is research that links zinc deficiency with higher rates of eating disorders. Some postulate that the physiologic symptoms of lack of taste and appetite are the connection there, but I think that it’s more likely to be the connection between low zinc levels and mood and psychological syndromes. Low zinc has also been associated with higher rates of schizophrenia, and more violent behaviors and criminal activity – so that shows a correlation between zinc and psychiatric disorders.
Zinc deficiency can cause loss of appetite and loss of taste. In fact, some naturopaths will use a Zinc Tally test to assess for zinc deficiency – they give the patient a weak zinc solution – if the patient can’t taste anything, they might be zinc deficient. Once their stores are replenished, the liquid tastes slightly metallic to them. It’s not a perfect science, but it can be a good, inexpensive screen for zinc deficiencies.
Zinc can also cause dry skin and dry, thinning hair. I have found a few patients who had hair loss related to hypothyroidism that did not reverse until we added more zinc to their regimen (thyroid hormones are needed for zinc absorption). Supplementing the hormones alone did not do the trick, but once we added the zinc, and the zinc could be better absorbed, the hair loss turned around.
The recommended daily allowance for zinc is 11mg for men and 8mg for women. Zinc deficiency is commonly treated with doses ranging from 25mg to 100mg daily, but care must be taken at higher doses to not create a copper deficiency, since too much zinc can deplete copper. Having said that the inverse is true – one of the risks of zinc deficiency is that copper levels can elevate to potentially toxic levels. It’s all a fine balance! When supplementation is needed, I like the zinc picolinate form as it has good absorption, and for younger kids a liquid zinc is usually easier.
To test zinc and copper levels in children, a hair mineral analysis is a good, non-invasive starting point. Blood test-wise, serum zinc levels are frequently measured, and can be a good indicator of deficiency. My favorite assessment is a micronutrient panel by a lab called Spectracell, which measures various vitamin and mineral levels in white blood cells. This is probably the most effective measure, it’s just a little less mainstream and may be harder to access for a lot of people. My colleague Dr. Emily Poccia wrote a good article about Spectracell testing here.
At the very least, make sure you are taking a good quality multivitamin that contains the RDA of zinc. Eat foods that are rich in zinc such as meat, eggs and seafood. Whole grains and legumes contain zinc but it is less absorbable due to the inhibitory effect of phytic acid on absorption. And if you have kids make sure they’re getting some zinc every day, to ensure their healthy growth and development!