"Dietary deficiencies" is a term that means you're not getting enough important nutrients from the food you eat, which can lead to health problems. Full definition
In my practice, I'm seeing an increasing number of pets with skeletal problems, organ failure and endocrine abnormalities caused by dietary deficiencies of essential nutrients. (healthypets.mercola.com)
One group at risk for dietary deficiency of B12 are vegans and vegetarians — B12 is only found in animal foods. (functionalhealthnews.com)
But the human liver normally stores enough vitamin B12 to last for years, so true dietary deficiency is extremely rare. (newscientist.com)