Vitamin B3 May Have Been Delivered to Earth by Meteorites
Posted on April 25, 2014
NASA-funded researchers say vitamin B3 may have been made in space and delivered to Earth by meteorites. NASA says the findings support a theory that the origin of life may have been assisted by a supply of key molecules created in space and brought to Earth by comet and meteor impacts. Karen Smith of Pennsylvania State University in University Park, Pa. is pictured above crushing meteorites with a mortar and pestle in Goddard's Astrobiology Analytical Laboratory. Smith is the lead author of the research.
Smith says in a statement, "It is always difficult to put a value on the connection between meteorites and the origin of life; for example, earlier work has shown that vitamin B3 could have been produced non-biologically on ancient Earth, but it's possible that an added source of vitamin B3 could have been helpful. Vitamin B3, also called nicotinic acid or niacin, is a precursor to NAD (nicotinamide adenine dinucleotide), which is essential to metabolism and likely very ancient in origin."
A University of Maryland Medical Center article explains the importance of B3 to human beings. The article says a B3 deficiency is rare in the U.S., although alcoholics can suffer from it. A mild B3 deficiency can cause indigestion, canker sores and vomiting. A severe deficiency can cause pellagra, which has symptoms of cracked skin, dementia and diarrhea.
Smith and her team analyzed samples from eight different carbon-rich meteorites and found vitamin B3 at levels ranging from about 30 to 600 parts-per-billion in each meteorite. There was less of the vitamin in meteorites from asteroids that had been more altered by liquid water. The researchers also found other pyridine carboxylic acids at similar concentration. Pyridine dicarboxylic acids were also found in the meteorites.
Smith says, "We discovered a pattern - less vitamin B3 (and other pyridine carboxylic acids) was found in meteorites that came from asteroids that were more altered by liquid water. One possibility may be that these molecules were destroyed during the prolonged contact with liquid water. We also performed preliminary laboratory experiments simulating conditions in interstellar space and showed that the synthesis of vitamin B3 and other pyridine carboxylic acids might be possible on ice grains."
The research paper was published here in the journal Geochimica et Cosmochimica Acta.