Former and Vitamin-Like Compounds

Eggs, liver, cantaloupe, oats and beans on dark wood
Choline and inositol, the two genuinely important vitamin-like compounds here, are found in eggs, liver, beans and grains
Infographic: former vitamins, vitamin-like compounds and never-vitamins
Some compounds were given a B number and lost it, such as PABA, orotic acid and pangamic acid; choline and inositol are genuinely important
3D illustration of a cell membrane with choline head groups
Choline is part of the phospholipids that build every cell membrane

The Pages (6)

📜

Former Vitamins

Every retired vitamin name, from B4 to B17 and F to U, and what each substance really is.

Read the deep dive →
🌸

Inositol

Former vitamin B8, a pseudovitamin studied for mood and polycystic ovary syndrome (PCOS).

Read the deep dive →
🥚

Choline

Former vitamin B4, now an essential nutrient for brain, liver and methylation, and widely under-consumed.

Read the deep dive →
🧴

PABA

Once sold as vitamin B10; not a vitamin, best known from the history of sunscreen.

Read the deep dive →
🥛

Orotic Acid

Former vitamin B13: a building block the body makes on the way to DNA and RNA.

Read the deep dive →
❓

Pangamic Acid

Sold as “vitamin B15”: not a vitamin, and with no fixed chemical identity.

Read the deep dive →

Prescription and over-the-counter drugs now have their own section: Pharmacology › Drugs.

Compounds sold as vitamins that are not. Some were given a B number and lost it (PABA as B10, orotic acid as B13, pangamic acid as B15), one never had a legitimate claim to the B17 it is still marketed under (laetrile), and two are genuinely important nutrients that simply are not vitamins — choline, which is essential, and inositol, which the body makes. The pages say which is which.

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