Top 3 Animal-Derived Vitamins Essential for Health

Historically, the diets of healthy nonindustrialized peoples throughout the world varied according to climate and terrain—but all of them can be described as nutrient-dense and rich in vitamins and minerals.

Weston A. Price, an influential researcher from Cleveland (1870–1948), analyzed some of these foods and found that the diets of “primitive peoples” contained four times more minerals than today’s average American diet. Of note were the high levels of naturally occurring, fat-soluble vitamins found in the food—vitamins A, D, and K2—which Price referred to as “activators.”

Without them, he noted, proper absorption of minerals such as iron, calcium, and iodine can’t occur.

These vitamins play myriad other roles and are essential to life and good health.

However, misinformation on fat-soluble activators abounds. The U.S. Department of Agriculture (USDA) dietary guidelines largely exclude sources such as butter, cream, full-fat cheese, lard, poultry fats, and organ meats such as liver that best provide these critical nutrients.

Vitamin A

When it comes to critical fat-soluble vitamins, we need to consider what I call the “vitamin A switcheroo.” Because the dietary guidelines suggest so little vitamin A, the USDA and the Food and Drug Administration (FDA) allow the food industry to label carotenes as vitamin A. Nutrition labels on packaged carrots or tomatoes state that they contain vitamin A—but your body actually converts vitamin A from beta-carotene, a precursor to vitamin A. Animals and humans can convert carotenes into vitamin A via an enzyme-intensive process in the gut.

In the natural world, ruminant animals spend most of their time transforming the carotenes in green grass into vitamin A, which they store in their organs, fat, and butterfat. In nature, carnivorous animals go straight for the true vitamin A-rich parts of their prey—the liver and other organs.

Some humans are able to convert carotenes fairly efficiently. However, a study in the U.K. found that nearly 50 percent of European women lacked the enzyme for this conversion. In fact, human beings vary greatly in their ability to convert beta-carotene to true vitamin A, with women being less able to make this conversion than men.

Beta-carotene has a dark side. In a study published in the Journal of Biological Chemistry in 2012, researchers from Ohio State University found that molecules derived from beta-carotene can block certain actions of true vitamin A. This discovery could explain why a previous clinical trial found that people who were heavily supplemented with beta-carotene had a higher incidence of lung cancer than participants who took no beta-carotene.

Diabetics convert carotenes with great difficulty—as do babies and children who need true vitamin A from egg yolks and liver as their first foods, not sweet potatoes and carrots. Intestinal absorption problems, poor thyroid function, poor liver function, consumption of food additives, heavy exercise, and exposure to pesticides and chemicals can all inhibit the conversion of carotenes to vitamin A.

It’s difficult for many people to depend on plant sources of carotenes for vitamin A, especially as this vitamin plays so many roles in the body.

Not only do we need vitamin A for mineral assimilation, especially calcium (which is why milk contains vitamin A-rich butterfat) but also for protein assimilation, an animal study suggests.

Vitamin A is essential for reproduction, proper growth, and the prevention of birth defects. Most hormones require vitamin A for their formation—including sex hormones, stress hormones, and thyroid hormones. We need vitamin A for our eyes, healthy skin and bones, and good hearing. Vitamin A supports energy production in the mitochondria, so it plays a role in combatting fatigue.

One of the most fascinating roles for vitamin A is support for feel-good chemicals and the ability to plan and complete tasks, suggests a review study published in Molecular Nutrition and Food Research in 2010 that looks at multiple previous studies to understand the effects of the vitamin in songbirds and rats. The study found that vitamin A deficiency had major implications for learning, maturation, and neurological development.

“Together these results yield significant insights into the role of vitamin A in maintaining neuronal plasticity and cognitive function in adulthood,” the researchers wrote.

Vitamin D

The second fat-soluble activator—vitamin D—also carries a cargo of misinformation.

Many sources on vitamin D insist that it’s difficult to get the sunshine vitamin from food—maybe a little from eggs, oily fish, vitamin D-fortified milk, or mushrooms, a source of D2, not the active animal form D3, but not enough to meet our needs.

The only options these sources present are sunbathing or taking vitamin D supplements.

Actually, many foods provide vitamin D: butter, whole milk, and cheese (especially if these come from pastured animals); shellfish such as shrimp; poultry liver; and poultry fat. Lard and bacon are excellent sources and eggs from chickens raised in the sunlight are vitamin D powerhouses. Then, there’s cod liver oil, which provides both A and D—and which most American children received right up to World War II.

Like vitamin A, we require vitamin D for so, so many things: healthy bones, of course, but also proper growth, mineral assimilation, muscle tone, reproduction and virility, healthy skin, insulin production, the nervous system, basic cell function, immune function, and the production of feel-good chemicals.

Vitamin K2

The third fat-soluble vitamin has an interesting history. Price wasn’t sure what it was—he called it the x factor—but he knew that traditional peoples got it in their diet from foods such as butter from grass-fed animals, animal fats, and liver. It acted as a co-factor to vitamins A and D—without the x factor, the other two activators were less effective. He believed that the x factor was largely responsible for the wide faces and freedom from dental decay that he observed among nonindustrialized peoples.

We now know that the x factor is vitamin K2, the form of vitamin K that animals make out of vitamin K1 in green-growing grass, and that sea animals make from plankton. A key role of vitamin K2 is making sure that calcium and phosphorus go to the right place—the bones and teeth—and don’t get lodged in the wrong places, such as the joints and arteries.

These three vitamins work together—vitamins A and D are hormone-like, providing signals to the cells to make certain proteins, while vitamin K2 activates the proteins after signaling from vitamins A and D.

That’s why we shouldn’t take isolated supplements of vitamins A, D, and K2. If we take vitamin D on its own—a very popular practice these days—we’re likely to develop deficiencies in vitamins A and K2, which could manifest as kidney stones, immune problems, or even depression.

The combination of K2 with vitamin D—very popular these days—is bound to lead to rapid vitamin A depletion. And the form of K2 in the supplements isn’t the x factor, not the animal form discovered by Price, but a form made by fermentation.

The best way to obtain these three critical nutrients is the fun way: by eating. Taking cod liver oil isn’t that fun, but there are ways to do it painlessly. And there are delicious foods in the Western diet that will provide these nutrients in the approximate right proportions, especially if these foods come from pastured animals: cheese omelets, caviar, and sour cream, butter sauces, pate, grass-fed bacon cheeseburgers, crispy chicken skin, potatoes cooked in duck fat, custards, creamed soups, and natural charcuterie.

Additional Sources

https://www.healthline.com/health/food-nutrition/empty-calories#identify

https://www.sciencedaily.com/releases/2009/11/091118072051.htm

Sabrina J Hickenbottom and others. Variability in conversion of beta-carotene to vitamin A in men as measured by using a double-tracer study design. Am J Clin Nutr.2002 May;75(5):900-7. https://pubmed.ncbi.nlm.nih.gov/11976165/

https://news.osu.edu/researchers-find-potential-dark-side-to-diets-high-in-beta-carotene—ohio-state-research-and-innovation-communications/

T Furusho and others. Tissue-specific distribution and metabolism of vitamin A are affected by dietary protein levels in rats.Int J Vitam Nutr Res.1998;68(5):287-92. https://pubmed.ncbi.nlm.nih.gov/9789760/

https://knowledgeofhealth.com/lack-of-vitamin-a-may-be-overlooked-root-of-tinnitus-and-hearing-loss/

Christopher R Olson and Claudio V Mello. Significance of vitamin A to brain function, behavior and learning. Mol Nutr Food Res.2010 Apr;54(4):489-95. https://pubmed.ncbi.nlm.nih.gov/20077419/

https://www.westonaprice.org/health-topics/abcs-of-nutrition/on-the-trail-of-the-elusive-x-factor-a-sixty-two-year-old-mystery-finally-solved/

https://www.westonaprice.org/health-topics/in-defense-of-vitamin-k2-mk-4-dr-prices-activator-x/