Vitamin B12 Deficiency as the Cause

In general practice, fatigue is a major topic in the consultation, especially with patients with non-acute conditions. The article mentions many causes. But I missed clearer indications of nutrition related and behavioral causes. On the one hand, in these times when a healthy and ethically justifiable diet is gaining in importance, dietary/nutritional habits should be an integral part of medical history taking. In all experience, especially younger patients have adopted a vegetarian or even vegan diet.

In the absence of adequate substitution of vitamins and iron supplements, this often results in a striking deficiencies in B vitamins, especially vitamin B12. Vitamin B12 deficiency can cause pronounced symptoms of exhaustion and fatigue, even in the low normal range. This cause should therefore always be considered in the context of the symptom fatigue and also tested for in the laboratory.

Furthermore, it is worth mentioning that vitamin D deficiency in patients who work long hours in indoor spaces (office, factory, warehouse, etc) or those who spend all their time indoors because of illness should be excluded, as vitamin D deficiency can be a contributing factor to other causes of fatigue.