Tuesday, July 7, 2015

Micronutrients: vitamins

So far I have been speaking about macronutrients. In order to be healthy we need to introduce them in quantities that are in the order of hundreds of grams (carbohydrates, fats and proteins) on a daily basis.

Micronutrients are nutrients that are needed in smaller amounts (less than one gram) with some being needed in traces. Despite the small requirements, they are fundamental for optimal health. Some of them are essential, meaning we have no choice and need to introduce them regularly through a balanced diet. Deficiencies in some micronutrients are the root cause of diseases such as:
  • Beri-Beri (Vitamin B1)
  • Ariboflavinosis (Vitamin B2)
  • Pellagra (Vitamin B3)
  • Paraestesia (Vitamin B5),
  • Hypocobalaminemia (Vitamin B12)
  • Scurvy (Vitamin C)
  • Rickets (Vitamin A, D, K2 and Calcium)
  • Night Blindness (Vitamin A)
  • Hypothyroidism (Iodine)
  • Anemia (Iron)
  • Kesha disease (Selenium)
Some conditions don't have a specific name but are still caused by micronutrient deficiencies:
  • Vitamin K deficiency (difficulty in coagulation)
  • Biotin deficiency (Vitamin B7)
  • Zinc deficiency (several non-life threatening signs and symptoms, zinc deficiency is far more widespread than usually thought)
The two lists are obviously incomplete, I just wanted the readers to realize how important these small molecules are and maybe scare them a little: you wouldn't believe how many people in the civilized world are borderline with the intake of some vitamins: bleeding gums is the first stage of scurvy.

Micronutrients are either molecules (vitamins, bioflavonoids, phytonutrients, enzymes, co-factors, ...) or elements (minerals). Today I'd like to introduce vitamins, the most important amongst the molecule micronutrients for one simple reason: they are essential, meaning we can't produce them.

Water soluble and fat soluble

There are two classes of vitamin, the water soluble (or hydrosoluble) vitamins and the fat soluble (or liposoluble) vitamins. The first are dissolved in water or other watery liquids. The second in fats, this detail is important because without healthy fats in the diet their absorption is impaired.

Fat solubleWater soluble
Vitamin AVitamin B1, 2, ..., 15
Vitamin DVitamin C
Vitamin ECholine
Vitamin KInositol
Para-Aminobenzoic Acid

Where to find them

You may have noticed that the main picture of the post shows one egg religiously fried in butter from grass-fed cows, some grass-fed beef liver, organic blueberries and pickled olives. Normally, a blogger would have introduced the subject with a rainbow of exotic fruits. But this is not simply a blog about on nutrition, this is YET another blog on nutrition, my role is to inform with state of the art of science, go against dogmata and - where needed - against Conventional Wisdom and ethics (don't hate me).

Fruits, vegetables, spices, herbs and whole grains are excellent sources of vitamins, bioflavonoids, anti-oxidants, anti-inflammatory compounds... This is where vegans are totally right. Anybody trying to do the Inuit Diet (a 100% meat/fish based diet) is doomed to fail on the long run, despite the initial benefits. Paleo dieters attempting to live on coconut, almonds and bacon simply didn't get what the original idea of paleo itself is... moreover they are experiencing miserable meals from an organoleptic point of view, but this is not me to judge: de gustibus non est disputandum.

The other side of the medal is that several vitamins and other micronutrients which are not perforce vitamins (and therefore less popularized) are only found in animal sources. This is where traditional diets got it right, as Weston A. Price observed during his researches: there is no native culture thriving on a plant-based diet. I would add a corollary: if any culture in the history of mankind ever tried to become vegan they are not here anymore to tell us.

The table below is a not-exaustive list of sources for the most common vitamins.

Egg yolks, liver, oily fish, dairy
Pork, yeast, avocado, wheat germ, spinaches, cauliflower, most nuts, sunflower seeds, legumes
Dairy, leavy vegetables, liver, kidney, legumes, yeast, mushrooms, nuts
Liver, heart, kidney, chicken, beef, oily fish, eggs, avocados, dates, tomatoes, leafy vegetables, broccoli, carrots, sweet potatoes, asparagus, nuts, whole grains, legumes, mushrooms
Almost any food
Meat (pork, turkey, beef), bananas, legumes, potatoes, pistachios, dairy, wheat germ
Swiss chard, raw egg yolks, liver. Can be produced by bacteria in a healthy gut
Almost any food, especially leafy greens, yeast, avocado, asparagus, dairy, meats, eggs
Seashells, egg yolks, liver
Bell peppers, kiwi, lemon, lime, oranges, grapefruits, pine needles, bovine adrenal glands
Egg yolks, liver, oily fish, dairy
Most nuts and seeds, olives, some fruits (kiwi, mangoes, papayas, avocados)
Egg yolks, liver, oily fish, dairy, lacto-fermented food
Almost any food, especially: egg yolks, yeast, wheat germ, fish, meat

Usual question: confused? Some may be. Let's look in detail some of these vitamins to clear some doubts.

Vitamin A

Carrots, apricots, melons and pumpkins, with their wonderful orange colors, are usually considered good vegetable sources of Vitamin A. Unfortunately this is untrue: they are sources of carotenoids, which are not the true Vitamin A, whose real name is retinol.
Some people are good at converting carotenoids into retinol, these are the exceptions, not the rule. Most humans are inefficient in this conversion and some cannot convert it at all, just like the conversion of the ω-3 ALA into DHA and EPA.

In other words: you can binge on carrots and still be Vitamin A deficient.

Vitamin D

This is my favourite vitamin, and it is also the most misunderstood. I started my health journey from here several years ago.
A typical mistake is considering nuts, seeds and their oils as sources of Vitamin D. There are two natural forms: Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). The one that is active in the human body is the D3 and is only found in animal sources.
It is also produced in our skin from cholesterol when we expose ourselves to sun rays, unfortunately the sun-phobia, our indoor jobs and the use of sunscreens greatly limit this conversion. Finally, not all of us work as lifesavers in the tropics, the average civilized humans are able to expose themselves to the sun only a couple of weeks per year. Definitely not enough.

In other words: if you expose yourself to the sun only for a short period during the year (and use sunscreen in that occasion), and if you rely on vegetable sources for vitamin D, you can still be Vitamin D deficient, with a number of consequences of health, both short and long termed.

Vitamin E

Let's speak in favour of vegetables now: there are no reliable sources of Vitamin E from animal sources. The group of Vitamins E is definitely from plants, with olives and their oil being by far the most excellent, tasty and versatile source.

In other words: the Mediterranean Diet with its big salads generously flooded with Extra Virgin Oil of Olive wins again.

Vitamin K

Again, there are several forms, with Vitamin K1 and Vitamin K2 being the ones naturally occurring and both being essential for optimal health.
There are no vegetable sources of Vitamin K2 , however this vitamin is the byproduct of the process of lacto-fermentation of some bacteria. Good vegetarian and vegan sources of vitamin K2 are: natto, tempeh, and dairy (especially yoghurt and aged cheese, for lacto-vegetarians).

Vitamin C

This is another Vitamin that comes preferably from plants. It is also highly delicate to oxidation and easily destroyed with temperatures: exposure to 60°C is enough to get rid of it. Now, some food for thought: the bottled orange juice sold in supermarkets is pasteurised, therefore...?

There are sources of Vitamin C from animals, namely the lungs and the adrenal glands. Considering that Vitamin C is quickly destroyed with temperatures, unless you are eating raw lungs and adrenals from freshly butched animals, this is not working for you (it works for the Inuits).

In other words: Vitamin C deficiency is quite widespread and although nowadays nobody is developing scurvy in the western world, for most people the intake is just slightly above the lower limit to prevent diseases. That enough to survive, but with sub-optimal health.

Vitamin B12

This is a hot topic. There are two forms of Vitamin B12. One is from vegetable sources, the other from animal sources. Once again, which one do we, humans, need? The one from animal sources.

However: some studies claim that Vitamin B12 can be produced inside the organism by probiotic bacteria, this is naturally done in the rumen of ruminants.

Can this be replicated in the human gut? There is a certain controversy on this: healthy bacteria usually populate the large intestine, where the Vitamin B12 cannot be absorbed (it is absorbed in the small intestine).

There are cases of vegans with serious Vitamin B12 deficiency after just 5 years, on the other side there are long term vegans (35+ years) which are perfectly healthy. Biochemical individuality? Probably. The question stays open.


Impossile to conclude here, there is still too much to say. I hope as usual to have answered some questions, but also to have stimulated your curiosity. Let me know in the comments your ideas.

The next topic will be the minerals, after that I will go back to practical examples and soon recipes. Therefore... stay tuned.


  1. Nice post ! Would be interesting to get more information on vitamin D: recommended dosage based on activity level, type of exercise (HIIT, hypertrophy weight training, strength training, etc.), list of benefits of vitamin D3 supplementation.

    1. Hello, it is already programmed ;) Vitamin D3 is fundamental, not only for bone health, but also for the immune system and the prevention of some forms of cancer, especially melanomas.

    2. What do You mean is already programmed?

    3. Warning, spoilers ;) In my agenda I plan to write articles on single vitamins, as well as herbs, spices, etc.