Vitamin B12 Sources and Absorption: Daisy's Guide

You wake up after eight hours of sleep and still feel drained. Your hands tingle, your mind is foggy, and everyone tells you it is stress or age. Daisy says this can be low vitamin B12, and that most people never test for it. She was deficient herself, and she changed how she handles this vitamin after she researched it.

What B12 does and how low levels feel

Daisy compares B12 to electricity in a house. You only notice it during a power cut, yet it quietly runs your nerves, energy and brain. She says about 6 in 10 Indians are deficient, and most do not know it.

She lists the signs she watches for:

• Constant tiredness, even after full sleep.
• Unexplained weight loss.
• Pale or yellowish skin.
• Tingling or numbness in the hands and feet.
• Balance problems, and blurry vision.
• Brain fog, poor memory, low mood, irritability and anxiety.

Doctors can mistake these for stress, ageing or even dementia. At 26, Daisy felt low and tired, and her mother said she was just getting old. Her B12 was 180, and she says the normal range starts at 200.

Why meat eaters run low too

Daisy quotes 65% of vegetarians and 46% of meat eaters as deficient. Her point is that eating B12 is not the same as absorbing it. Your body needs enough stomach acid, a protein called intrinsic factor, and a healthy small intestine. If one is weak, you can eat meat daily and still run low.

She names habits that can interfere:

• RO water. She says reverse-osmosis filtering removes cobalt, the mineral B12 is built around. It also kills water microbes that once supported your B12 status. She quotes a 40% higher deficiency risk for long-term users.
• Antibiotics. They wipe out helpful gut bacteria, and she says B12 recycling stops without them.
• Metformin. This diabetes medicine is a known risk. Daisy notes that doctors often prescribe a supplement alongside it.
• Antacids. Less stomach acid means less B12 released from food.
• Heavy, regular alcohol. It can damage the stomach lining and intrinsic factor.
• Age. After 50, she says intrinsic factor production drops naturally.

If you take medicine for this, keep your doctor in the loop.

Which foods give B12

Daisy’s view is that gut health decides everything, so her meals include fermented foods such as idli, dosa, dhokla, miso and sauerkraut. She says fermentation can make trace amounts of B12 and help release it from food. She does not treat them as a main source.

On other foods, she says:

• Meat and fish. Meat is the most bioavailable source. But she says factory-farmed animals are given B12 in their feed, so you get supplemented B12 second-hand. She cites the UN Food and Agriculture Organization for this.
• Eggs. She says 96% of the B12 is tightly bound to protein, so only 3 to 9% is absorbed. One egg gives about 0.5 micrograms.
• Dairy. She calls it about three times more bioavailable than meat. But she says boiling, pasteurising and fermenting cut it by 25 to 50%, so milk alone needs many glasses.
• Mushrooms, moringa, barley, wheatgrass and tempeh. She says some contain B12, but amounts vary and some is inactive. She does not rely on them.
• Nori seaweed. She calls this a real exception: one sheet has about 77 micrograms, according to her. At roughly ₹17 a sheet, she finds it costly for daily use.

Fortified foods and nutritional yeast

Daisy’s “best bet” is fortified food and supplements. She says that, unlike B12 bound inside animal protein, added B12 is already free. Your body can absorb it straight away.

Her main food source is nutritional yeast. She says a quarter cup gives 8 to 24 micrograms of B12. It is grown from yeast, not animals, and then fortified. Her tip is to add small amounts to every meal, because several small doses beat one big dose.

Choosing a B12 supplement: dose and form

Daisy gives three points to check before you buy.

Dose. She quotes 2.4 micrograms a day for an adult, 2.6 in pregnancy and 2.8 while breastfeeding. For older adults she mentions 100 to 500 micrograms. Tablets list much higher numbers because only 1 to 2% of a high dose is absorbed, she says, and the rest leaves in urine. She calls high doses safe and non-toxic. Her rule is to get a blood test first and ask your doctor about the right dose.

Form. Cyanocobalamin is lab-made and stable, and your body converts it. Daisy says it works if your gut is strong. Methylcobalamin is already active, so she recommends it for a sensitive or damaged gut. She likes it paired with folate (B9) and B6, which she says work as a team.

The plant-based myth. Some people think vegan B12 is weaker. Daisy says B12 is made by microbes, not by plants or animals. A vegan tablet comes from microbial fermentation, and the molecule is the same.

She also mentions a mouth-dissolving methylcobalamin strip. She says it skips the gut, so it can act faster in severe deficiency or poor absorption. When she began supplementing years ago, she says her level was normal within three weeks.

What research says

Research backs several of Daisy’s points. A review by food scientist Fumio Watanabe notes that egg B12 seems poorly absorbed, at under 9%. It also says dried purple laver (nori) holds substantial B12, and that fortified breakfast cereals help vegans and older people. A later review explains that B12 is made only by certain bacteria, not by plants or animals. Plants and mushrooms rarely hold much of it.

A laboratory study of Korean purple laver found true B12 in dried and toasted products, though seasoned and toasted types held less.

On medicines, a large Kaiser Permanente study found that two or more years of acid-reducing drugs went with a higher chance of B12 deficiency. In the Diabetes Prevention Program follow-up, longer metformin use was linked to a higher chance of low B12. These studies show links, not proof of cause. Daisy’s figures on RO water, how common deficiency is and the animal-feed point are her own claims, so check them with your doctor.

Daisy’s tips

• Test your B12 before you supplement, and ask your doctor for your dose.
• Add fermented foods to every meal, but do not count on them as your B12 source.
• Sprinkle nutritional yeast in small amounts across the day.
• Look for methylcobalamin with folate and B6 if your gut is sensitive.
• Buy from trusted chemists such as Tata 1mg, Apollo or Wellness Forever.
• Still tired after about four months of supplements? See your doctor about other causes.

Daisy walks through every step in the video above. It takes about 13 minutes.