But various other, unapproved peptides have been touted on TikTok, in podcasts, and by health-tech startups as ways to reverse signs of aging, repair tissue, relieve pain, and improve cognitive performance, among other claims
MCT oil (medium-chain triglycerides) Origin: MCT oil is usually obtained from coconut oil
Many of the peptides being sold have not been adequately tested for safety, effectiveness, quality, or long-term effects

Symptoms of Low Vitamin B12 Neurological symptoms: Tingling or numbness in the hands, feet, or legs Balance problems and unsteady gait (posterior column degeneration) Weakness in the legs Memory impairment, difficulty concentrating, and brain fog Mood changes, depression, or irritability Vision changes from optic nerve involvement (less common) Hematologic symptoms (megaloblastic anemia): Fatigue and weakness Pallor or slight jaundice (lemon-yellow skin tint from ineffective erythropoiesis) Shortness of breath during exertion Rapid heart rate Other signs: Glossitis a sore, smooth, bright-red tongue Mouth ulcers Unintended weight loss What Causes Low Vitamin B12 Pernicious anemia: autoimmune destruction of gastric parietal cells producing intrinsic factor (most common cause in adults over 50) Strict vegan or vegetarian diet without B12 supplementation (B12 is found almost exclusively in animal products) Metformin use (reduces ileal B12 absorption over time) Long-term proton pump inhibitor (PPI) use Gastric bypass or gastrectomy surgery Celiac disease or Crohns disease affecting the terminal ileum Chronic heavy alcohol use Aging (reduced intrinsic factor production and gastric acid) Normal Vitamin B12 Levels | Measure | Reference Range | |---|---| | Vitamin B12 | 190-950 pg/mL (varies by lab) | Functional B12 deficiency with neurological symptoms can occur at levels between 200 and 300 pg/mL technically normal on many lab reports
