The Rejected B Vitamins: Why B4 to B17 Aren’t in Your Multivitamin
Facts The Missing B Vitamins: What Happened to B4, B8, B10–B17?
What Makes a Compound a "Vitamin"?
To be officially classified as a vitamin, a substance must:
Be essential for normal body function
Not be synthesized by the body in sufficient quantities
Cause deficiency diseases when absent from the diet
Be required in small amounts
All the missing "B vitamins" failed to meet one or more of these criteria.
Vitamin B4
Old Names: Choline, Adenine, Carnitine (confused historically)
Choline: Now a conditionally essential nutrient (needed more during pregnancy/liver disease).
Adenine: A DNA/RNA base — not a vitamin, as the body produces it.
Why dropped? These compounds are made in the body or not needed in trace amounts like real vitamins.
Today:
Choline = important, but not a vitamin
Adenine = genetic material component
Carnitine = important for fat metabolism, but made in the body
Vitamin B8
Old Name: Inositol
Role: Supports brain, nerves, insulin sensitivity
Status: Not essential, as body synthesizes inositol from glucose
Why dropped? No disease from inositol deficiency has been identified.
Today:
Used as a supplement (especially for PCOS, anxiety)
Sometimes called a "pseudo-vitamin"
Vitamin B10
Old Name: PABA (Para-Aminobenzoic Acid)
Role: Once thought to be essential for folic acid synthesis in bacteria
Why dropped? Not essential for humans — we don’t make folic acid from PABA
Used in: Sunscreens, hair products, some medicinal uses
Today:
Still sold as a supplement, but not a vitamin
May interfere with sulfa antibiotics
Vitamin B11
Old Name: Pteryl-hepta-glutamic acid, part of folate group
Confusion: In some countries, B11 = folate; in others, it referred to another folate-like compound
Why dropped? Because folate (B9) covered its role
Today:
No longer used as a separate vitamin
Folate = B9, and that’s enough for human needs
Vitamin B13
Old Name: Orotic acid
Role: Involved in DNA/RNA formation and cell growth
Why dropped? Produced by the body, and no known deficiency disease
Still studied for liver support and metabolic disorders
Today:
Used in some supplements, but not considered a vitamin
Vitamin B14
Old Name: Unclear, some say xanthopterin
Role: Once thought to support cell growth
Why dropped? No consistent evidence of benefit or deficiency effect
Today:
Considered obsolete, very little mention in modern science
Vitamin B15
Old Name: Pangamic acid
Used in: USSR and alternative medicine as an “anti-aging” or “oxygenation” compound
Why dropped? No proven benefit, banned in U.S. as a supplement due to safety concerns
Today:
Still sold in some places as “B15,” but not legally recognized as a vitamin
Vitamin B16
Old Name: Dimethylglycine (DMG)
Role: Claimed to boost energy, immunity, endurance
Why dropped? Made by the body and not essential
Today:
Marketed as an energy or brain supplement, but not a vitamin
Vitamin B17
Old Name: Amygdalin / Laetrile
Found in: Apricot kernels, bitter almonds
Claimed Role: "Anti-cancer vitamin" — but highly controversial and dangerous
Why dropped?
Contains cyanide
No scientific evidence of cancer cure
Banned in many countries
Today:
Sold in alternative circles as “B17,” but NOT a vitamin and potentially toxic
In the 1970s and 1980s:
Laetrile was widely promoted as an alternative cancer cure
Supporters claimed it selectively killed cancer cells
People began eating raw apricot kernels as a natural source
But…
Apricot kernels contain amygdalin, which the body converts into cyanide — a poison.
Real Cases of Poisoning
Case 1: A 17-year-old girl in the U.S. in the 1980s died of cyanide poisoning after taking Laetrile tablets.
Case 2: In the UK and Australia, multiple cases of acute cyanide toxicity were reported from eating apricot kernels. Some required hospitalization.
Case 3: In 2017, the Australian Medical Association warned against a man who nearly died after taking 17 daily tablets of “natural B17” extract.
Suggested Reading -
FDA Issues Warning About Toxic Amygdalin Found in Apricot Seeds
Laetrile (amygdalin or vitamin B17)
