Vitamin B12: What It Does, Who Needs It, and How to Get Enough

When your body runs low on vitamin B12, a water-soluble nutrient critical for nerve function, red blood cell production, and DNA synthesis. Also known as cobalamin, it’s not made by the body—you have to get it from food or supplements. Without enough, you might feel tired for no reason, get numbness in your hands or feet, or struggle to focus. It’s not just about being low on energy—it’s about your nervous system and blood cells literally struggling to work right.

Many people think they’re getting enough B12 because they eat meat, but that’s not always true. Older adults, vegetarians, people with gut issues like Crohn’s or celiac, and those on long-term acid-reducing meds often can’t absorb it properly—even if they eat plenty of it. Your stomach needs acid and a protein called intrinsic factor to pull B12 from food. If either is missing, you’re at risk. That’s why a blood test is the only real way to know if you’re deficient. Symptoms like brain fog, mood swings, or tingling in your fingers don’t always show up until levels are seriously low.

Where do you actually get it? animal products, like meat, fish, eggs, and dairy are the main sources. Clams and beef liver have crazy high amounts—just a few ounces can cover your daily need. For vegans, fortified cereals, plant milks, and nutritional yeast are the only reliable options. But here’s the catch: supplements aren’t always better than food. Oral pills work fine for most, but if your body can’t absorb B12, you’ll need injections or high-dose sublingual tablets. Doctors often recommend injections for people with pernicious anemia, a condition where the body attacks the cells that make intrinsic factor.

Don’t assume you’re fine just because you don’t feel sick. B12 deficiency creeps up slowly. It can mimic aging, stress, or depression. One study from India found nearly 70% of healthy adults had low B12 levels—not because they were vegetarian, but because of poor absorption from chronic inflammation or gut imbalances. That’s why it’s not just a diet issue—it’s a health issue. If you’re over 50, have digestive problems, or take metformin for diabetes, get tested. It’s a simple blood test. Fixing it early means avoiding nerve damage that might never fully reverse.

Below, you’ll find real advice from people who’ve dealt with B12 deficiency, what doctors in India actually recommend, and how supplements stack up against food. No fluff. Just what works.