The Oxford dictionary definition is accurate and succinct. “Any of a group of organic compounds which are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be synthesized by the body.”. Specifically with a focus on the fat soluble vitamins today, we have vitamins A, D, E, F, and K. I believe fat soluble nutrients don’t receive the attention they deserve, they are essential, they participate in many functions of the human body, and fat solubility in our modern world, plagued with gall bladder removals, poor fat digestion, low fat diets and abysmal dietary advice, fat soluble nutrients need someone to make their case for them and in here to do that.
Where Shall we Start? Alphabetically!
Also known as retinol, its active aldehyde form – retinal, and acid. Vitamin A plays very significant roles in childhood development, immunity – particularly in TH1 immune responses in our mucosa, and eyesight. This last study conveniently highlights an important distinction between true vitamin A and its precursors known as pro vitamin A or carotenoids. The study shows the animal tissues didn’t contain these precursors and only the true vitamin A was detected. I think this demonstrates an important distinction between vitamin A and carotenoids, insofar as the fact that the tissues require real vitamin A. This study demonstrates how low absorption of carotenoids, and an even lower rate of conversion to true vitamin A in the body (as low as 5% even in optimal conditions) and this doesn’t even consider the epidemic of gastrointestinal disorders, as the carotenoids can only be absorbed at such a rate in healthy intestine, and the rate will be surely decreased further with digestive disorders. The take away here is to consume plenty of real, preformed vitamin A, and this is easy. You’ll be seeing a trend in the post about fat soluble vitamins and that will be to consume your fatty animal products. For vitamin A you absolutely cant beat liver, but egg yolks, oily fish, and other organ meats are also great sources. It’s better to assume that the carotenoids you are consuming don’t count towards your vitamin A intake, you’ll find it very hard to overdose on vitamin A without concentrated supplements. It’s probably worth nothing also that, although carotenoids aren’t necessarily a good source of vitamin A, they still have an enormous array of health benefits , and you can still enjoy them and reap the benefits.
Vitamin D3 has become very popular. Yogurts, milk and cheese. Cereals and spreads are all being fortified with vitamin D, but why? And why are they being added in synthetically now? We didn’t used to fortify our foods so what are we missing that out ancestors didn’t? Firstly, vitamin D is being added to foods because it’s a vitamin! Its vital, and not enough vitamin D3 has serious health consequences. This journal states “Vitamin D deficiency causes rickets in children and will precipitate and exacerbate osteopenia, osteoporosis, and fractures in adults. Vitamin D deficiency has been associated with increased risk of common cancers, autoimmune diseases, hypertension, and infectious diseases.” And I cant agree more. Clearly vitamin D deficiency is dangerous and should be addressed, but should adding vitamin D to our foods be the way we do it? no argument, the best way to get vitamin D is the way nature intended us to get it, sunlight! You’ve probably heard it called the sunshine vitamin before and for good reason. “During exposure to sunlight, ultraviolet radiation penetrates into the epidermis and photolyzes provitamin D3 to previtamin D3.”. So the real solution to vitamin D deficiency is to make sure you sunbathe regularly and responsibly.
Vitamin E plays its largest role as an antioxidant. This is significant because antioxidants are most commonly water soluble, but fats are very sensitive to oxidation, so vitamin Es fat solubility serves a very niche purpose. Vitamin E is abundantly easy to obtain on almost any good quality diet, and deficiency is very rare, and more often caused by poor absorption than lack of dietary intake.
Vitamin F is a fun one, and it’s also likely the least discussed, until you realise what it is. Vitamin F are essential fatty acids, namely ALA (alpha-linolenic acid) EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid). These fat soluble nutrients are all omega 3 fatty acids, and they are very important during developmental stages, primarily for brain and nervous system development. They also have anti inflammatory properties. Its important to consume ALA EPA and DHA, because even though the body can convert ALA to EPA and EPA to DHA the conversion rates are unsustainably low  – around 5%. Without a doubt the best sources of these omega 3 fatty acids are fish, particularly the fattier fish. Salmon, mackerel and sardines are great but all seafood is excellent. Also worth noting that any animal products that are grass fed will have higher levels of omega 3, as grass fed animals diets are richer in omega 3 from the grass they consume, in comparison to the omega 6 heavy grain fed animals. Because omega There’s are largely present in nervous system tissue, brain and eyeballs are also great, perhaps less appealing, sources of omega 3 fats.
Vitamin k1, also known as phylloquinone, is used by the body in many functions, but primarily in blood clotting. K1 is generally found in plants, particularly the leafy green type. Vegetable like kale and spinach are your best bet.
Vitamin K2 also know as menaquinone play a very important role in bone density . Working alongside vitamin D, Vitamin K2 tells calcium, magnesium and other materials to be stored inside the bone structure. Many believe consuming more calcium will help with poor bone mineral density but the true problem isn’t that they don’t have enough calcium, instead, the vitamin k2 deficiency means the calcium isn’t being deposited where its needed. This also has a negative effect on cardiovascular health as excess calcium is not removed from the blood, and its documented that atherosclerosis is correlated with calcium plaques in the arteries. The best sources of vitamin k2 are the wholefood fatty foods that are yellow and orange in colour. Butter, cheese, egg yolks and cream are the best, you will find some in all animal products including tallow, lard and organ meats. It’s also worth noting you can actually obtain a good amount of K2 from fermented foods, in particular Natto: a fermented soy product.
Fat is your friend, and so are the vitamins it contains. Its important to remember that by dry mass the human body is 50% animal fat and 50% animal protein, and if that doesn’t provide you with some clues as to how important a part fat plays in your diet, then I don’t know what will!