Last week we talked about magnesium deficiency and there were an AMAZING number of people who contacted me feeling they might be deficient. This week I want to talk about another very important mineral. Could you be deficient in zinc?
In a word, yes. Just like with magnesium, about half of Americans don’t get enough zinc in their diet. The US RDA for zinc is around 10 mg (a little less for women, a little more for men and for women who are pregnant or breastfeeding). The elderly, those with chronic medical conditions (such as chronic kidney disease, sickle cell disease, alcoholism and liver cirrhosis), teenagers, pregnant women and vegetarians are more likely to be deficient.
Vegetarians?! Why vegetarians? A plant based diet is very healthy, right? Why would vegetarians be prone to zinc deficiency? Well it turns out that some of the richest dietary sources of zinc are meat, seafood, dairy and egg yolks (whole grains, nuts, seeds, beans and legumes are also good sources). Also, soy and fiber intake (both of which tend to be high in the diet of vegetarians) decrease the absorption of zinc. Yikes. (For those of you who don’t know, I’ve been vegan for about 3 1/2 years.)
Medications and supplements can interfere with zinc absorption. Some blood pressure medications (especially diuretics), steroids, antibiotics and some antacids either interfere with zinc absorption or increase loss of zinc in the urine. Calcium, iron, vitamin B6 and N-acetylcysteine supplementation interfere with zinc absorption.
What happens when you’re zinc deficient? Two common symptoms are a decreased sense of taste and loss of appetite. We used to hear this in the nursing home all the time – “I’m not hungry, nothing tastes good.” Were we chalking it up to depression and treating zinc deficiency with an antidepressant? Maybe. If any of you readers are nursing-home nurses, please advocate for zinc replacement for your patients if you hear this complaint!
Other symptoms of zinc deficiency are depression, anxiety, poor concentration, jitteriness, white spots on the fingernails, tremor, night blindness, erectile dysfunction, low sperm count and testosterone, frequent infections, slow wound healing, hair loss and anemia.
How do you know if you’re zinc deficient? Unfortunately, just as with magnesium there aren’t good, accurate tests to detect mild to moderate zinc deficiency. Blood tests just measure what’s in the blood (which is very tightly regulated) and urine tests vary unpredictably.
As with magnesium, it seems that if you have symptoms of zinc deficiency a reasonable thing to do is to try modest zinc supplementation and see if you feel better. Many zinc supplements provide 5 mg of zinc per dose (about half what the average person needs). It is difficult to overdose on zinc but large doses can cause abdominal pain, nausea, vomiting, diarrhea, headache and a metallic taste in the mouth.
A reasonable trial of zinc supplementation would be 20-30 mg of elemental zinc daily for a few weeks to see if symptoms improve. This dose would not be likely to cause any side effects. Shaklee’s zinc supplement is Zinc Complex which also has a little calcium in it. If someone were concerned about possible zinc deficiency I would suggest 2 tablets daily for a month and see if symptoms improve.
In case you’re wondering why I recommend Shaklee supplements, I discuss that here.
I suspect I may be adding Zinc Complex to my daily routine, since I am vegan and eat lots of both soy AND plant fiber. What about you?
QUESTION: Do you have any symptoms of zinc deficiency?