For thousands of years, humans knew that certain foods could treat certain ailments. However, why or how the foods did this was totally unknown.
It wasn’t until the early 20th century that researchers discovered exactly what chemicals were in food that prevented and cured many diseases.
Today, that knowledge has led to an entire industry dedicated to providing and supplementing nutrients.
Learn more about vitamins, what they are, how they were discovered, and what happens if you lack them in your diet on this episode of Everything Everywhere Daily.
A while back, I did an episode where I told the story of how the 18th-century Scottish doctor James Lind found that citrus fruits could prevent and cure scurvy.
He, like most sailors, knew what scurvy did, but he had no clue why it happened, nor did he really know why citrus fruits like limes and lemons seemed to cure it. All he knew was that it worked.
By the early 20th century, the three macronutrients had been identified: fats, proteins, and carbohydrates.
However, whatever else was in food that might provide health benefits was still unknown. For example, the magical property in limes that prevented scurvy was still unknown.
Another navy doctor, Takaki Kanehiro of the Japanese Imperial Navy, did a study of naval crew members and the disease beriberi in 1884. Beriberi can result in a deterioration of the nervous system, numbness in the extremities, and in extreme cases, death.
Kanehiro noted that beriberi only affected the low-ranking sailors on his ship and not the officers. The difference, he thought, was the diet. Low-ranking sailors only ate rice, whereas officers ate more varied meals.
He received approval to run a test on the diet of crew members on two ships. One ship only ate white rice, whereas the other ate a variety of foods.
On the ship that only ate rice, there were 161 cases of beriberi and 25 deaths. On the ship with a varied diet, there were only 14 cases with no deaths.
The issue of beriberi was a far more serious problem in Asia than it was elsewhere in the world.
Japanese researchers kept investigating the problem, and in 1910, the chemist Umetaro Suzuki isolated a compound found in the bran of rice which he called aberic acid. It was later dubbed thiamine.
It was the first vitamin to be discovered.
Not long after, the English biochemist Frederick Hopkins proposed that there were other things in food beyond the three macronutrients, which he called “accessory factors.”
Many researchers didn’t make note of Suzuki’s discovery because of problems with the translation of his research paper.
In 1912, the Polish researcher Casimir Funk isolated a nutrient that he considered an anti-beriberi nutrient. He initially dubbed his new nutrient
“Vitamine”, but it was later changed to niacin.
“Vitamine” came from the words “vital” and “amine”, which is a type of chemical.
“Vitamine” soon because synonymous with all the “accessory factor” chemicals, not a singular one, and it was changed to “vitamin” when it was found that not all of the essential chemicals have an amine part.
So, what is a vitamin?
Vitamins are essential organic nutrients necessary for metabolism that are found in food.
Here I need to explain what an “essential nutrient” means because the word is a bit misleading. Essential implies that something is necessary, and to be sure, all of the vitamins are necessary for survival.
However, in this case, essential means something that our bodies cannot produce ourselves. The human body cannot produce vitamin C, for example, but most mammals can. So, for human beings, vitamin C is an essential nutrient, but it isn’t an essential nutrient for dogs or cats.
Not all essential nutrients are considered to be vitamins. There are minerals that we need, like iron, calcium, and copper, that our bodies cannot create, but they aren’t considered vitamins because they are not organic.
Likewise, there are some amino acids that our bodies cannot produce as well. These are not considered vitamins because they are proteins.
Currently, 13 vitamins are generally recognized, and sometimes a 14th.
Most vitamins are not single chemical molecules but rather a collection of molecules that perform similar functions. These groups are called vitamers.
Vitamins are classified by their solubility. There are four fat-soluble vitamins and nine water-soluble vitamins. Generally speaking, water-soluble vitamins will be excreted if they are not used and your body can’t store them.
Fat-soluble vitamins, as the name suggests, can be stored in body fat. This can lead to its own problems, as we’ll see in a bit.
So what are the 13 vitamins?
Let’s just go alphabetically and start with vitamin A.
Vitamin A is a collection of molecules, most usually retinol. In its raw form, vitamin A is only found in animal products, which surprises most people because people think carrots are high in vitamin A. What is found in plants like carrots is beta-carotene which is a provitamin.
Provitamins are chemicals that can be converted to vitamins in our bodies. The efficiency at which our bodies can convert beta-carotene to vitamin A is determined by genetics and can vary greatly between people. Conversions can range from 3.6 to 1, all the way to 28 to 1.
A vitamin A deficiency can lead to night blindness and other eye disorders, and it is especially damaging to children.
Because it is fat-soluble, vitamin A can actually be toxic if too much is consumed. It is almost impossible to do for most people, but consumption of polar bear liver can lead to Hypervitaminosis A, which can be fatal….so, don’t eat polar bear liver.
Next is vitamin B, which is actually a whole category of eight vitamins. Many of these vitamins were given their own letter at one point and then renamed with a B.
All the B vitamins are water-soluble and, despite being lumped together, are distinct from each other.
Vitamin B1, also known as Thiamine. This was the first vitamin that was isolated, and a B1 deficiency can lead to beriberi. It can be found in liver, eggs, and a host of vegetables. Most importantly, for rice-consuming countries, it was found that if you just consume the brown bran coating on rice, you’d get thiamine which would prevent beriberi.
Vitamin B2 is known as riboflavin. It is most commonly found in dairy products, but it is also in asparagus and bananas. B2 deficiency is pretty rare as B2 is fortified in many wheat products, and if you have a B2 deficiency, you probably also have some other deficiency as well.
Vitamin B3 is also known as niacin. It is found in a variety of foods, but it is notability lacking in corn. A B3 deficiency is known as pellagra, which can result in very nasty skin lesions. It was common in South and Central America due to their high corn diet. Today it can be found in poorer countries, in refugees, and in people with alcoholism. It was very common in prisoners held in Soviet gulags.
Vitamin B5 is known as Pantothenic acid. A deficiency of B5 is known as Paresthesia. Its primary symptoms are a feeling of pins and needles on your skin.
Vitamin B6 is a collection of molecules, most commonly pyridine.
Vitamin B7 is known as Biotin. It is most commonly found in eggs and peanuts.
Vitamin B9 is known as Folic Acid or Folate. Folates and folic acid are extremely important during pregnancy, as a deficiency can cause birth defects.
Finally, there is B12. B12 is probably the most chemically complex molecule of all the vitamins. It was synthesized in 1972 in a process so complex that it isn’t even commercially viable.
B12 is unique because it cannot readily be found in any plants. The only natural source comes from animal products.
B12 deficiency is known as Pernicious anemia, and it is a serious problem in many vegetarian and vegan communities as it requires artificial supplementation. Pernicious anemia can result in irreversible brain and never damage.
If you ever see “enriched flour,” it is usually enriched with B vitamins.
Vitamin C is next, and as I mentioned, I’ve previously done an entire episode on it and scurvy. Unlike other vitamins, there is only one chemical version of vitamin C.
The role of vitamin C is to help create collagen, which is one of the most important proteins in your body. It literally helps connect your tissue, which is why scurvy can be so painful.
Vitamin D is considered a single vitamin, although, unlike other vitamins, its vitamers are often listed separately, D1 through D5.
Vitamin D is found in food, but it can also be produced by our skin when it is exposed to sunshine.
It is fat-soluble, and a severe vitamin D deficiency is called rickets. Rickets is uncommon in developed countries, but they were much more common in the ancient world. It usually affects children and can result in deformed bones.
A general vitamin D deficiency is probably the greatest deficiency problem for any vitamin today. It is mostly because people spend more time indoors and don’t get as much sun exposure as they used to.
Low vitamin D levels have been linked to a whole host of medical problems, including increased incidents of cancer, heart disease, ADHD, and increased COVID-19 mortality.
Vitamin E is an important antioxidant that is found in many grains and seeds, as well as in seafood. Vitamin E deficiency is very rare, given the prevalence of seed oils in the world today.
The last vitamin is vitamin K. There are two variants of vitamin K, K1 and K2. K2 is like B12 in that it is not found in plants. The main problem of vitamin K deficiency is the inability of blood to coagulate.
I’ve really given just a cursory overview of each of the vitamins. You could probably write an entire doctoral dissertation. There is a lot to unpack for each one with the various sources of each vitamin, bioavailability, the effectiveness of different vitamers, and a host of other issues.
You might be wondering where vitamins F and G are? They go in alphabetical order and then jump from E to K.
Vitamin F was used for the essential fatty acids alpha-linolenic acid and linoleic acid. However, it was determined that they weren’t actually vitamins, so they were recategorized as fats. They are still nutrients you need to get through food, but not vitamins.
Vitamin G was the original name given to riboflavin, which is now called vitamin B2.
In fact, many of the B vitamins were given alternative names. Biotin was vitamin H, for example.
I mentioned before that there is sometimes a 14th vitamin on some lists. The 14th vitamin is occasionally given the name Vitamin J, but it is more commonly called choline.
Choline is essential, but it behaves a bit more like an amino acid which is why it usually isn’t listed as a vitamin.
Vitamins have become a big business. The global dietary supplement industry was estimated to be 151.9 billion dollars in 2021, which included all supplements, not just vitamins.
There has been a lot of debate in health and nutrition circles about how effective vitamin supplements are. Some claim they are absolutely essential, and others who say they are useless.
I’m certainly not a health expert, but from the research I’ve seen, there tend to be two things most would agree on. Even if supplements don’t do much good, they also probably don’t do much harm.
Also, you are usually better off getting the nutrients you need from food. Natural nutrients from meats, fruits, and vegetables will almost always be more bioavailable, meaning they are easier for your body to absorb and use.
The discovery of vitamins was one of the greatest advances in medicine in the 20th century. Seventeen people have received Nobel prizes for their work, either directly or indirectly, on the discovery of vitamins.
Thanks to our knowledge of vitamins, we know not only what to eat but what it is in our food that makes us healthy.