Q. I was taken aback by your remarks about limiting the number of Brazil nuts eaten. Many years ago when I was growing up, my parents bought nuts at Christmastime. Brazil nuts were my favorites and I ate tons of them. I continued the tradition as an adult. I ate lots myself and gave them to my children.
I have not seen Brazil nuts much recently and I seldom eat them. But what did I do to my health and my children’s with all these nuts?
A. Any health problems that might arise as a result of excess selenium would fade after you were no longer eating Brazil nuts or other selenium-rich foods. Selenium is a little bit like Goldilocks’ porridge: you need enough, but not too much.
The most common symptoms of selenium poisoning are seen in hair and nails. They can become quite brittle and fall out. Other problems you might have noted around Christmastime could have included rash, stomach upset, irritability or fatigue.
The tolerable upper limit of selenium is 400 micrograms a day for adults and less for children. An ounce of Brazil nuts, about half a dozen, may contain as much as 800 micrograms of selenium, so it makes sense not to gorge on too many too often.