The Vitamin Story

William McComb • July 24, 2026

Share this article

The Vitamin Story

In the late 1800s and early 1900s, scientists realized that diseases such as:


  • Scurvy
  • Beriberi
  • Pellagra
  • Rickets


weren’t caused by infections, but by the absence of tiny dietary substances.


At the time, every newly discovered substance thought to be essential was simply given the next letter of the alphabet.


So we started with:

  • Vitamin A
  • Vitamin B
  • Vitamin C
  • Vitamin D
  • Vitamin E


Scientists assumed many more vitamins would follow.


Instead, many of the compounds that were initially called vitamins turned out to be:

  • mixtures of other vitamins,
  • amino acids,
  • fatty acids,
  • or substances the body could manufacture itself.


Their letters were retired.


Vitamin B became an entire family

The biggest surprise was vitamin B.


Scientists originally thought vitamin B was one chemical.

Later they realized it contained many completely different compounds.


Today we know them as:

  • B1 — thiamine
  • B2 — riboflavin
  • B3 — niacin
  • B5 — pantothenic acid
  • B6 — pyridoxine
  • B7 — biotin
  • B9 — folate
  • B12 — cobalamin


Notice the missing numbers?


Those numbers were assigned to substances later shown notto be vitamins.


What happened to Vitamin F?

Vitamin F turned out not to be a vitamin.


It was actually:

  • linoleic acid
  • alpha-linolenic acid


These are essential fatty acids.

Because they’re fats—not vitamins—the name was abandoned.


What happened to Vitamin G?

Vitamin G eventually became:

Vitamin B2 (riboflavin).

Scientists realized it belonged with the B-complex rather than being its own vitamin.


Vitamin H

Vitamin H became:

Biotin (Vitamin B7).

The H came from the German word Haut (skin), because deficiency affected the skin.


Vitamin I

Never officially accepted.

Several compounds were proposed but none met the definition of a vitamin.


Vitamin J

Sometimes used experimentally for catechol or other compounds.

Never became an official vitamin.


Vitamin L

Originally thought to promote lactation in animals.

Later shown not to be an essential human vitamin.


Vitamin M

This became:

Folic acid (Vitamin B9).

“M” came from “monkey,” where it was first studied.


Vitamin N

Occasionally used for lipoic acid.

Today alpha-lipoic acid is considered an important metabolic cofactor but not a vitamin because humans can synthesize it.


Vitamin O

Never validated.


Vitamin P

One of the more interesting ones.

Vitamin P referred to:

bioflavonoids such as:

  • quercetin
  • rutin
  • hesperidin

These compounds reduce capillary fragility and work alongside vitamin C.

They are beneficial but are not considered vitamins because deficiency doesn’t produce a well-defined disease.


Vitamin Q

Sometimes referred to:

Coenzyme Q (CoQ10).

Again, humans manufacture it.

Therefore it isn’t classified as a vitamin.


Vitamin R

Several compounds received this designation over time.

None remained vitamins.


Vitamin S

Never accepted.


Vitamin T

Sometimes referred to carnitine or other growth factors.

Since humans synthesize carnitine (assuming adequate vitamin C, iron, lysine, and methionine), it lost vitamin status.

This ties into your recent interest in vitamin C and carnitine—although carnitine is nutritionally important, it isn’t technically a vitamin because healthy people usually make enough of it.


Vitamin U

Very interesting.

Vitamin U is actually:

S-methylmethionine

found in cabbage juice.

It showed promise for stomach ulcers decades ago.

It is beneficial but not considered an essential vitamin.


Why did we jump to Vitamin K?

Vitamin K was discovered much later.


The researcher who identified it was Danish biochemist Henrik Dam, who noticed chickens fed a fat-free diet developed bleeding problems. He named the factor “Koagulationsvitamin” because it was required for blood coagulation. The “K” comes from the German and Scandinavian spelling of “coagulation,” not because it was the next unused letter of the alphabet.


Later we learned there are multiple forms:

  • K1 (phylloquinone) from green plants
  • K2 (menaquinones) produced by bacteria and found in fermented foods and animal products


So what is a vitamin?

Modern nutrition defines a vitamin as a compound that:

  • is required in very small amounts,
  • cannot be synthesized in sufficient quantities by humans,
  • has a defined biochemical role,
  • and whose deficiency causes a characteristic disease or syndrome.


Many substances once labeled as vitamins—such as CoQ10, carnitine, lipoic acid, bioflavonoids, and essential fatty acids—are undeniably important for health, but they don’t meet all of these criteria. Some are made by the body, while others are required in larger amounts or do not produce a specific deficiency disease.


An interesting perspective

The history of vitamin discovery also highlights how scientific understanding evolves. Early researchers correctly sensed that foods contained many essential factors beyond protein, fat, and carbohydrate. As analytical techniques improved, scientists separated these factors into distinct vitamins, amino acids, essential fatty acids, trace minerals, and numerous bioactive compounds. Today we recognize that health depends on far more than the classic 13 vitamins. Compounds such as omega-3 fatty acids, choline, lutein, carotenoids, polyphenols, CoQ10, and others play important physiological roles, even though they are not officially classified as vitamins.


Recent Posts

Woman in workout clothes looking at her reflection in a mirror beside a bathroom scale in a bright r
By William McComb • October 13, 2026
Discover why weight loss takes more than eating better and exercising more, and explore the deeper factors that can influence metabolism, appetite, and progress.
By William McComb • October 13, 2026
Your Skin Isn’t Built in a Bottle!
By William McComb • September 29, 2026
Beef Liver & Anemia How three physicians turned a simple food into a lifesaving treatment Less than 100 years ago, pernicious anemia was often a death sentence.  Patients became exhausted, pale, weak, and short of breath. Some developed confusion, numbness, difficulty walking, and permanent nerve damage. Physicians watched helplessly as the disease progressed because no effective treatment existed. Then three American physicians—Dr. George Whipple, Dr. George Minot, and Dr. William Murphy—looked in an unexpected direction: food.
By William McComb • September 9, 2026
The Truth About Aging, Metabolism, Hormones, and Why There Is a Smarter Way to Lose Fat
By William McComb • August 31, 2026
Kristine’s Transformation: Finding Herself Beyond Food For years, Kristine was “the foodie” among her friends — the party planner who organized restaurant nights, cooking classes, and elaborate gatherings centered around food. 
By William McComb • August 31, 2026
David’s Transformation: Science-Backed Results That Changed Everything  David, 49, was the type of person who believed every problem could be solved with enough discipline and data. A successful software designer and self-proclaimed “data geek,” he arrived at Rx Weight Loss & Wellness carrying years of spreadsheets documenting every failed attempt to lose weight .
By William McComb • August 31, 2026
Beyond the Scale: Joseph’s Heart Health Transformation Joseph, 68, spent decades working hard as a construction foreman. Long hours, stress, and years of gradual weight gain had become “normal” to him. He brushed it off as simply getting older — “just a dad bod,” as he called it. Then came the chest pain. An emergency room visit revealed something far more serious happening beneath the surface. A coronary calcium scan showed early atherosclerotic plaque buildup, while his labs painted the classic picture of metabolic dysfunction: insulin resistance, elevated triglycerides, low HDL cholesterol, and rising inflammation. What shocked Joseph most was learning that visceral abdominal fat wasn’t just cosmetic weight — it was actively damaging his blood vessels and accelerating cardiovascular disease every single day. Four months after beginning GLP-1 therapy as part of his medically supervised program, Joseph’s health story changed dramatically. He lost 22 pounds — but the real transformation was happening internally. His A1C dropped from 6.3% to 5.2%. His triglycerides normalized. Follow-up imaging showed stabilization of arterial plaque progression. His energy improved, his breathing became easier, and his inflammation markers fell significantly. For the first time, Joseph understood that metabolic health and heart health are deeply connected. “I used to think protecting my heart meant avoiding steak,” he said. “Now I understand the real danger was the invisible metabolic damage happening inside my body every day.” Joseph’s journey is a powerful reminder that GLP-1 therapy is not simply about losing weight on a scale. By improving insulin sensitivity, reducing visceral fat, and calming chronic inflammation, these treatments may help reduce cardiovascular risk and restore metabolic health before irreversible damage occurs. Results vary.
By William McComb • August 31, 2026
From Burned Out to Built Back: Mark’s Journey From Exhaustion to Unstoppable Energy Mark, 57, looked successful from the outside. A high-performing CEO and former collegiate athlete, he had spent his entire life believing that discipline, intensity, and hard work could overcome anything. But after years of stress, travel, poor recovery, and gradual weight gain, his body no longer responded the way it once had. His energy crashed. His metabolism slowed. His workouts left him exhausted instead of stronger. When Mark began GLP-1 thera py at Rx Weight Loss & Wellness , h e immediately attacked the process the same way he approached business and sports — with maximum intensity. Daily workouts. Aggressive cardio. Heavy training sessions. Three weeks later, he was frustrated, sore, depleted, and losing motivation fast. “I feel like I should be able to do more, not less,” he admitted. What Mark was experiencing is something many patients never realize: during rapid metabolic change, the body needs strategic adaptation — not punishment. We helped Mark completely reframe his approach. Instead of pushing harder, we built a sustainable metabolic performance plan tailored to his changing physiology while on GLP-1 therapy. We scaled him back to: • Two focused 30-minute strength sessions weekly • Daily walking with strategic HIIT intervals • Recovery-focused programming • Higher protein intake to preserve lean muscle and metabolism • Gradual progression instead of burnout At first, Mark struggled mentally with doing “less.” But within weeks, his body began responding in ways it hadn’t in years. His energy stabilized. His recovery improved. His inflammation dropped. His workouts became productive again instead of draining. Six months later, Mark had lost 42 pounds while building a sustainable fitness routine he could actually maintain long term. More importantly, he stopped viewing exercise as punishment and started using it as a tool to strengthen his metabolism, protect muscle, and support longevity. “The difference this time,” Mark said, “is that I’m no longer fighting my body. I’m finally working with it.” Mark’s transformation highlights one of the biggest keys to success during GLP-1 therapy: the right strategy matters. Extreme workouts and burnout are not the answer. Consistency, recovery, muscle preservation, and expert guidance create lasting transformation. A t Rx Weight Loss & Wellness , w e don’t just prescribe medication — we help patients build a complete metabolic strategy designed for real-world success. Results vary.
By William McComb • August 27, 2026
More Than Weight Loss: Sally’s Turning Point Sally, 54, walked into RX Weight Loss & Wellness feeling defeated. Her blood pressure was 168/98. LDL cholesterol: 182. A strong family history of heart disease. She tracked every calorie, went to the gym three times a week, and did everything she thought she was “supposed” to do. Yet her health markers kept getting worse. “I’m doing everything right, but my body won’t cooperate,” she said. What weighed on her most wasn’t just the number on the scale — it was the constant mental battle with hunger, cravings, and exhaustion. Six months after starting tirzepatide as part of her medically supervised program, Sally lost 28 pounds — but the biggest transformation was happening inside her body. Her blood pressure normalized to 118/76 without medication. Her cholesterol and inflammatory markers improved dramatically. And for the first time in years, she described feeling mentally free. “I finally don’t think about food every waking moment.” Sally’s journey is a reminder that GLP-1 medications aren’t simply about appetite suppression. For many patients, they help address deeper metabolic dysfunction — improving health, lowering cardiovascular risk, and restoring confidence and quality of life. Results vary.
By William McComb • August 10, 2026
GHK The Signaling Peptide That Helps Turn Your Genes On and Off
Show More