Even though vitamin B12 is found in many foods, its insufficiency and deficiency are relatively common. Low B12 symptoms can vary from physical to psychological.
Studies suggest that up to 20% of people over the age of 60 in the United States and the United Kingdom are deficient in the vitamin.
This is often due to limited dietary intake, malabsorption, medical conditions, or the use of B12-depleting medications.
Want to know more: https://www.healthline.com/nutrition/vitamin-b12-deficiency-symptoms