Vitamin B9: History and Discovery

The discovery of Vitamin B9 began not in a laboratory but in a maternity ward in Bombay, where a young English doctor named Lucy Wills noticed that poor pregnant women were dying of a severe anaemia that rich women rarely got. In 1931 she showed that a cheap yeast spread — Marmite — could cure it, proving that the cause was something missing from the diet. For years that something was simply called the "Wills factor." It took another decade of work by chemists, who finally isolated it from spinach leaves in 1941 and named it folic acid — from the Latin folium, "leaf" — before two rival pharmaceutical teams crystallised it, worked out its structure, and, in 1945, built the molecule from scratch. This article tells that story honestly: who saw the deficiency first, who isolated and named the vitamin, the genuine race between two companies to purify it, the long roster of chemists who synthesised it, and the surprising way the very same research gave the world its first cancer chemotherapy. Where the record is firm we say so; where priority is shared or a claim is uncertain, we say that too.

Table of Contents

  1. What Vitamin B9 Is, and Its Many Names
  2. Lucy Wills and the Anaemia of Pregnancy (1931)
  3. The Hunt for the "Wills Factor"
  4. Isolated from Spinach, Named for the Leaf (1941)
  5. A Race Between Two Companies: Crystallisation and Structure
  6. Built from Scratch: The 1945 Synthesis
  7. An Unexpected Legacy: The First Cancer Chemotherapy
  8. Casimir Funk, the Word "Vitamine," and the Question of a Nobel Prize
  9. From Discovery to Fortified Bread: The Modern Era
  10. Research Papers and References
  11. Connections
  12. Featured Videos

What Vitamin B9 Is, and Its Many Names

Vitamin B9 is the modern label for a single nutrient that goes by several names, and it helps to sort them out before the history begins. Folate is the general term for the vitamin and for the natural forms found in food and in the body. Folic acid is the specific, fully oxidised, man-made form first synthesised in the 1940s and now added to fortified flour and many supplements. The chemists who worked out its structure called it pteroylglutamic acid, after the three chemical pieces it is built from. All of these are forms or names of the same B vitamin.

The name folate — and its synthetic cousin folic acid — comes from the Latin word folium, meaning "leaf," because the vitamin was first concentrated from green, leafy plants such as spinach. That origin is not a coincidence of marketing; it is a direct trace of the discovery itself, because the leaf was literally where the substance was found. The story of how a nameless "factor" in food became a named, mapped, and manufactured molecule unfolds over roughly fifteen years, from 1931 to the mid-1940s, and it is one of the better-documented discovery stories in the whole vitamin family.

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Lucy Wills and the Anaemia of Pregnancy (1931)

The central figure at the start of this story is Dr. Lucy Wills (1888–1964), an English physician and researcher who, in the late 1920s, travelled to India to study a severe and often fatal anaemia that struck pregnant women, especially poor textile workers in Bombay (now Mumbai). The condition looked like pernicious anaemia, but it did not behave like it, and no one knew its cause. Wills approached the problem like a detective. She noticed that better-off women, who ate a richer and more varied diet, were far less likely to develop the anaemia — a clue that pointed away from infection and toward nutrition.

To test the idea she turned first to animals and then to her patients. In a landmark paper published in the British Medical Journal in 1931, "Treatment of ‘pernicious anaemia of pregnancy’ and ‘tropical anaemia’ with special reference to yeast extract as a curative agent," Wills reported that a cheap, widely available yeast extract — the familiar British spread Marmite — could correct the anaemia when purified liver extracts (the standard treatment for pernicious anaemia) often could not. This was a genuinely important result: it showed that the disease was caused by a dietary deficiency, and that the missing ingredient was present in yeast but was not the same as the anti-pernicious-anaemia factor in liver (which we now know to be vitamin B12).

It is worth being precise about what Wills did and did not do. She did not isolate a chemical, give it a name, or determine its structure — the tools to do that did not yet exist. What she did was identify the existence of a previously unknown dietary factor and prove it could cure a deadly disease. That is the foundational act of the whole folate story: the recognition of the deficiency and its dietary cure. The substance she had detected without ever seeing came to be known, fittingly, as the "Wills factor."

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The Hunt for the "Wills Factor"

Through the 1930s the "Wills factor" was a known unknown: a real, biologically active substance that cured a real disease, but a substance no one had yet held in a tube. Nutritional science of the era was full of such factors — activities defined entirely by what they did in animals or patients rather than by their chemistry. Researchers working with chicks, monkeys, and bacteria kept turning up growth-promoting and anti-anaemia factors in yeast, liver, and green leaves, and for a while these went under a confusing scatter of names: "vitamin M" (studied in monkeys), "vitamin Bc" (a growth factor for chicks), the Lactobacillus casei factor (named for the bacterium whose growth it supported), and others.

A crucial later insight was that several of these separately named factors — the Wills factor, vitamin M, vitamin Bc, and the L. casei factor — were turning out to be the same vitamin, or closely related forms of it, viewed through different experimental windows. Untangling that knot is a large part of why the discovery took more than a decade and involved many laboratories at once. The story has no single lone genius; it is a relay, beginning with Wills’ clinical observation and passing through the hands of nutritional chemists, microbiologists, and finally pharmaceutical chemists who could purify and build the molecule. The next stage of that relay finally gave the vitamin its lasting name.

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Isolated from Spinach, Named for the Leaf (1941)

The vitamin got its name in 1941, and the name came straight from where it was found. Working at the University of Texas, the chemists Herschel K. Mitchell, Esmond E. Snell, and Roger J. Williams concentrated a microbial growth factor from spinach leaves and reported it in the Journal of the American Chemical Society. Because the richest source they had worked with was green, leafy material, they called the substance "folic acid," from the Latin folium, meaning leaf. It is one of the rare cases where a vitamin’s everyday name records the exact experiment that produced it.

This 1941 work is usually cited as the origin of the name "folic acid," though it is fair to note a subtlety the careful histories observe: what Mitchell, Snell, and Williams had was a concentrated, biologically active preparation from leaves, not yet a pure, crystalline, structurally defined chemical. The naming came first; the pure substance and its structure came a few years later, from a different and much larger effort. Both steps matter, and conflating them is a common error. The leaf gave the vitamin its name in 1941; the bottle of pure crystals, and the map of the molecule, arrived between 1943 and 1945.

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A Race Between Two Companies: Crystallisation and Structure

Here the folate story acquires a feature many vitamin histories lack: a genuine, well-documented priority race between two competing pharmaceutical research groups. As the historian Irwin H. Rosenberg lays out in his 2012 review in Annals of Nutrition and Metabolism, two industrial teams set out independently to purify the elusive factor. One was led by Robert Stokstad (often written Bob Stokstad) at Lederle Laboratories in Pearl River, New York; the other by Joseph John Pfiffner at the Parke-Davis Research Laboratory. The two groups worked from different starting materials — Lederle from bacterial (fermentation) cultures, Parke-Davis from yeast and liver — and both succeeded in isolating substances with the biological properties of the Wills factor.

Stokstad is generally credited with obtaining the pure crystalline form, around 1943, and with the work that led to determining its chemical structure. That structure explained the chosen chemical name, pteroylglutamic acid: the molecule is built from a pteridine ring system joined to para-aminobenzoic acid and to glutamic acid. Knowing the structure was the essential bridge between a mysterious dietary "factor" and a molecule that chemists could, in principle, manufacture at will.

The honest way to describe this episode is as parallel and competing discovery rather than a single winner. Both Lederle and Parke-Davis isolated active material; the Lederle group, with Stokstad, is the one most consistently credited in the literature with the crystalline pure form and the structural work that fed directly into the first total synthesis. This kind of shared, slightly contested priority is normal in the history of vitamins, and it is more accurate to name both teams than to award the discovery to one person.

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Built from Scratch: The 1945 Synthesis

The capstone of the discovery came in 1945, when chemists at Lederle Laboratories achieved the first laboratory synthesis of the vitamin — building pteroylglutamic acid from simpler chemicals rather than extracting it from food. The result was announced in a short, now-famous report in the journal Science, titled "Synthesis of a Compound Identical with the L. casei Factor Isolated from Liver." The author list is remarkable for its length — a roll-call of more than a dozen chemists, with Robert B. Angier listed first and including both E. L. R. Stokstad and Yellapragada Subbarow among the team. Synthesising the molecule proved beyond doubt that the structure was correct and made it possible to produce folic acid in quantity, cheaply and reliably.

The team that accomplished this became known informally as the "folic acid boys," working under the direction of Dr. Yellapragada Subbarow, an Indian-born biochemist who was director of research at Lederle. Subbarow is one of the more under-recognised figures in twentieth-century biochemistry, and the folic acid synthesis is among his major achievements. (It is worth noting that some popular accounts compress the timeline by saying the vitamin was "crystallised in 1945"; the more precise account is that crystallisation came earlier, around 1943, and 1945 marks the first total synthesis.)

With synthesis achieved, the arc that began with Lucy Wills was essentially complete: a deficiency disease had been recognised (1931), the responsible factor isolated and named (1941), its crystalline form obtained and its structure solved (1943), and the molecule itself manufactured from scratch (1945). What no one anticipated was that the very same chemistry was about to open a completely different chapter of medicine.

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An Unexpected Legacy: The First Cancer Chemotherapy

One of the most consequential twists in the folate story is that mastering the vitamin almost immediately led to the first effective drug treatment for a cancer. Once chemists could build pteroylglutamic acid, they could also build close look-alike molecules that the body would mistake for folate but that would jam the machinery folate normally runs — so-called folate antagonists or antifolates. The reasoning, advanced by the Boston pathologist Sidney Farber, was that since folate drives the rapid cell division seen in leukaemia, a drug that blocked folate might slow the disease.

The Lederle team, including Subbarow’s group, synthesised such antagonists, notably aminopterin. In 1947–1948 Farber used aminopterin to treat children with acute leukaemia and, for the first time, achieved temporary remissions — a watershed moment widely regarded as the birth of modern cancer chemotherapy. Farber acknowledged the contribution of Subbarow and his team in his landmark 1948 report. A refined, more manageable relative of aminopterin, methotrexate (originally amethopterin), followed and remains in wide use today for cancer and autoimmune disease.

This is a striking illustration of how basic discovery pays unexpected dividends: the campaign to understand a vitamin that prevents anaemia handed medicine a tool to fight cancer, simply because understanding a molecule well enough to build it also means understanding it well enough to block it. The mechanism cuts both ways, which is precisely why drugs like methotrexate require careful folate management — a theme explored on the main Vitamin B9 page.

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Casimir Funk, the Word "Vitamine," and the Question of a Nobel Prize

Folate’s story sits inside a larger one: the very idea that tiny amounts of specific dietary substances are essential for health. That idea, and the word for it, came from the Polish-born biochemist Casimir Funk, who in 1912 proposed the term "vitamine" — a blend of vital and amine — for the dietary factors whose absence caused deficiency diseases such as beriberi, scurvy, pellagra, and rickets. The final "e" was later dropped to give vitamin, once it was clear that not all of these substances are amines. Funk did not discover folate; he was working two decades before Lucy Wills’ study. But his framework is the reason the "Wills factor" was eventually recognised as a vitamin at all, and it is why B9 carries a B-number in the first place.

On the matter of a Nobel Prize, honesty requires a clear statement: the discovery of folate was not recognised with a Nobel Prize, and neither Lucy Wills, nor Mitchell, Snell and Williams, nor the Lederle and Parke-Davis chemists received one for this work. (Casimir Funk himself, despite coining "vitamine," was never awarded a Nobel either.) This sets folate apart from some other B vitamins whose discovery touched Nobel-winning research. We mention it deliberately, because the temptation to attach a Nobel Prize to a famous discovery is strong — and in this case it would be wrong. The folate story is a story of clinical insight and industrial chemistry, richly documented and genuinely important, but it was not a Nobel story.

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From Discovery to Fortified Bread: The Modern Era

Once folic acid could be made cheaply, the question became how to get enough of it to the people who needed it — above all, women in early pregnancy. The decisive modern findings came in the late 1980s and early 1990s, when controlled trials, most famously the British Medical Research Council Vitamin Study reported in The Lancet in 1991, demonstrated that folic acid taken around the time of conception dramatically reduced the risk of neural tube defects such as spina bifida. This was the discovery’s ultimate vindication: the same vitamin Lucy Wills had chased through a Bombay maternity ward turned out to protect the developing spine and brain of the unborn child.

Those trials led many countries, beginning with the United States in 1998, to fortify staple foods such as flour and cereal grains with synthetic folic acid — a public-health measure that has measurably reduced neural-tube-defect rates wherever it has been adopted. Fortification also opened the modern debate, central to natural-medicine practice, about the differences between synthetic folic acid and the body’s natural folate forms (such as 5-MTHF), and about how common genetic variations like MTHFR affect the way people use the vitamin. Those topics — and the full picture of what folate does in the body, from DNA synthesis to mood — are covered in detail on the main Vitamin B9 page and in the Vitamin B9 Benefits articles. This history is concerned only with how the vitamin came to be known in the first place: a story that runs, unbroken, from a doctor’s careful eye in 1931 to the fortified loaf of bread on the shelf today.

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Research Papers and References

The list below combines the key primary papers and historical reviews that document folate’s discovery with curated PubMed topic-search links. Author names, titles, and journals are given as plain text; only the stable DOI, PMID, PMC, or archive link is hyperlinked, and each opens in a new tab.

  1. Wills L. Treatment of "pernicious anaemia of pregnancy" and "tropical anaemia" with special reference to yeast extract as a curative agent. British Medical Journal. 1931;1(3676):1059–1064. — PMC2314785 (reprinted as a Nutrition Classic, PMID: 355948)
  2. Angier RB, Boothe JH, Hutchings BL, Mowat JH, Semb J, Stokstad ELR, Subbarow Y, Waller CW, Cosulich DB, Fahrenbach MJ, Hultquist ME, Kuh E, Northey EH, Seeger DR, Sickels JP, Smith JM Jr. Synthesis of a compound identical with the L. casei factor isolated from liver. Science. 1945;102(2644):227–228. — doi:10.1126/science.102.2644.227
  3. Rosenberg IH. A history of the isolation and identification of folic acid (folate). Annals of Nutrition and Metabolism. 2012;61(3):231–235. — doi:10.1159/000343112 (PMID: 23183294)
  4. Hoffbrand AV, Weir DG. The history of folic acid. British Journal of Haematology. 2001;113(3):579–589. — doi:10.1046/j.1365-2141.2001.02822.x (PMID: 11380441)
  5. MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. The Lancet. 1991;338(8760):131–137. — PMID: 1677062
  6. Lucy Wills, the Wills factor, and the discovery of folate — PubMed: Lucy Wills and the history of folic acid
  7. History of the discovery and synthesis of folic acid — PubMed: folic acid discovery and synthesis history

External Authoritative Resources

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Connections

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