Vitamin B12 on a vegan diet: how to get enough of it

What B12 is, and why it matters on a vegan diet

B12 lets the body make red blood cells and keeps the nervous system working normally. It is almost entirely absent from vegetables, beans, grains and fruit as they grow. B12 is made by bacteria living in soil and in animal guts, which is why meat, fish, eggs and dairy carry it in useful amounts. Anyone eating vegan full-time — particularly a fully vegan diet with no eggs or dairy — is likely to run short over a long period unless they supplement it.

Signs worth noticing

A B12 shortfall arrives slowly rather than dramatically. The common signs:

• Persistent tiredness despite sleeping enough, and a pale look to the skin
• Numbness or pins and needles in the hands and feet
• Forgetfulness and trouble concentrating
• A red tongue and soreness in the mouth

All of these have other possible causes; having them does not confirm a B12 problem. A blood test is the reliable way to know. Do not guess and then start taking a high dose on your own.

Who is more at risk

The group to watch is anyone who has eaten fully vegan for two or three years without ever supplementing. Women who are pregnant or breastfeeding on a vegan diet need to be more careful still, because the requirement rises. Older people, vegan or not, also absorb B12 less well, since the stomach produces less acid with age.

Two ways to cover it

Fortified foods

Some nut milks, breakfast cereals and nutritional yeast have B12 added, and say so on the packaging. Turn the label over and read the ingredients — do not assume, because plenty of vegan products are not fortified at all.

Tablets, lozenges or drops

B12 tablets are widely available in pharmacies, commonly at 500 to 1,000 mcg a day, or as directed on the box. B12 is water-soluble, so the excess is generally passed in urine rather than accumulating the way some fat-soluble vitamins do. That said, this is general information and not a substitute for a doctor's advice. Anyone pregnant, with an existing condition, or on long-term medication should ask a doctor or pharmacist before settling on a dose.

Where a vegan banh mi fits, honestly

To be straight with our customers: the loaves at Banh Mi XANH are built on tofu, vegan cold cut and fresh vegetables. Those give plant protein, fibre and a range of other vitamins — but they are not a natural source of B12. Treat a Thập Cẩm at 59,000d or a Đậu Hũ Cay at 56,000d as a good, filling meal, and cover B12 separately through fortified food or a supplement as described above.

Ordering vegan banh mi for delivery

If you want a vegan meal quickly, call 0923.183.183 or come to one of the five shops: 38 Lê Thị Riêng, 15B Nguyễn Thị Minh Khai, 2B Trần Hưng Đạo and 148B Đề Thám in District 1, and 210 Bùi Văn Ba in District 7. The shops are open 24 hours and deliver, free on orders from 500,000d within 5km. Alongside the loaves there is Nut Milk Coffee at 45,000d and Brown Sugar Nut Milk Bubble Tea at 48,000d.

Quick questions

Does a full-time vegan diet always mean a B12 shortfall?

Not inevitably — it depends on whether you supplement and on how well you absorb it. But eating fully vegan for years with no supplement at all makes a shortfall fairly likely.

Is a daily B12 tablet harmful?

B12 is water-soluble and the excess is generally passed in urine rather than stored. Even so, keep to the dose on the packaging, and do not raise it over a long period without asking a doctor or pharmacist.

Can plenty of leafy greens replace it?

No. Greens are rich in iron and folate but contain virtually no B12 in a form the body can use. They are different nutrients — do not let one stand in for the other and skip B12.

Is the banh mi at Banh Mi XANH fortified with B12?

No. The loaves are made with tofu, vegan cold cut and fresh vegetables, which are not fortified foods. Cover B12 separately with a supplement, or with a product whose label states that B12 has been added.

How often should B12 be tested?

There is no single interval for everybody. Anyone eating fully vegan over a long period can ask for B12 to be included in a routine check-up, typically once a year, or sooner if something seems off.