PQQ, a new kind of vitamin

The next time someone tells you to mind your p’s and q’s, don’t take offense. The subject may be nutrition, not manners — pyrroloquinoline quinone (PQQ), the first new vitamin in more than half a century. The water-soluble compound, identified at the University of Texas in 1979 and labeled a vitamin four years later by researchers at Tokyo’s Institute of Physical and Chemical Research, is widely available in plant foods such as green tea, green bell peppers, papaya, spinach, carrots, cabbage, and bananas. Animal studies show a connection between PQQ and an enzyme used by mammals to digest lysine, an amino acid found in proteins. The vitamin is essential for some bacteria and maybe even mice. And you? Well, if you need it, you need very, very little. The amounts of other vitamins are measured in milligrams (thousandths of a gram) or micrograms (millionths of a gram). But PQQ is measured in nanograms (billionths of a gram) — 1/1,000,000,000.Which is about as itty-bitty as it gets.