Berna Namoglu/Shutterstock Two micrograms is an almost unimaginably small amount. It weighs less than a tiny fragment of a grain of table salt. Yet adults need only around this amount of vitamin B12 each day, depending on the guideline used, to support red blood cells, nerves and DNA production. In 2026, it is 100 years since George Minot and William Murphy reported that a liver-rich diet could treat pernicious anaemia, then a frequently fatal disease. Their work transformed medicine and eventua