Any of these, alone or in combination, may explain a drop in stamina without pointing to a serious issue
Mitochondrial Biogenesis: Enhancing the efficiency of the electron transport chain and increasing the basal metabolic rate of adipocytes
Vitamin B12 injections can help increase energy levels, and keep red and nerve cells healthy
[124] Other causes of B 12 malabsorption include bariatric surgery, pancreatic insufficiency, obstructive jaundice, tropical sprue, celiac disease, inherited intrinsic factor deficiency, and radiation enteritis affecting the distal ileum
Nutritional Status (Anthropometry and Blood Analytes), Blood Pressure and Physical Activity
Vitamin B12 plays a big role in keeping your body healthy