An inverse correlation is observed between plasma PYY and BMD in populations with weight gain and obesity (decreased PYY and increased BMD) and in weight loss scenarios (increased PYY and decreased BMD), as observed in patients with anorexia and amenorrheic athletes [81]

Other groups who may benefit include: Patients following gastric surgery (gastrectomy, bariatric procedures) where intrinsic factor production or absorption sites are compromised Individuals with malabsorption disorders such as Crohn's disease, coeliac disease, or chronic pancreatitis Strict vegans and vegetarians with dietary insufficiency, though oral supplementation is usually tried first Elderly patients with atrophic gastritis or reduced gastric acid production Patients on long-term metformin or proton pump inhibitors, which can impair B12 absorption [6] [8] Individuals with nitrous oxide exposure (recreational or medical), which can cause functional B12 deficiency Diagnosis typically involves serum B12 measurement, with levels below approximately 148 pmol/L (though thresholds vary between laboratories) generally indicating deficiency
Important: This table represents general state Medicaid program policies
Without it, fatigue, mood changes, and even nerve problems can set in
Are they clinically meaningful