Vitamin B Deficiency Causes and Risk Factors

Causes of Vitamin B Deficiency

The most common causes of vitamin B deficiency are low dietary intake, malabsorption issues, medication use, and age-related physiological changes, according to the Proceedings of the Nutrition Society 1, 2
Food-bound malabsorption is the most common cause of B12 deficiency, primarily due to atrophic gastritis which affects up to 20% of older adults 2
Low dietary intake is the primary cause of folate deficiency 1, 2
Poor consumption of green leafy vegetables, legumes, and liver contributes to folate deficiency 2
Medication interactions can affect absorption of folate and other B vitamins 4
Malabsorptive conditions can contribute to deficiencies of multiple B vitamins 2
Increased requirements during pregnancy can lead to folate deficiency 4
Low dietary intake of milk, dairy foods, and fortified cereals contributes to riboflavin deficiency 1, 2
Age-related changes in requirements and low consumption of lean meat, milk, dairy foods, and fortified cereals contribute to vitamin B6 deficiency 2
Medication interactions can affect vitamin B6 metabolism 5

Older adults (aged 65+ years) are at significantly higher risk of vitamin B deficiency due to age-related physiological changes, multiple medication use, reduced food intake, and limited dietary variety 2, 5
Socioeconomic factors, such as lower socioeconomic status, can reduce access to fresh, nutrient-dense foods and lead to less varied diets 5, 6
Medical conditions, including gastrointestinal disorders, cancer, and diabetes, can affect nutrient absorption and metabolism 5

B vitamin deficiencies are associated with increased risk of cardiovascular disease, cognitive dysfunction, osteoporosis, depression, and anxiety 2
Dietary diversification with emphasis on lean meat, milk, dairy foods, green leafy vegetables, legumes, liver, and fortified breakfast cereals can help prevent vitamin B deficiencies 2
Increased fortification levels of B12 in foods for older adults may be beneficial 2