Essential nutrients - what do we need to eat?

[lpetrich]

For human nutrition, there are six types of essential nutrients. Some are needed in much greater quantity than some others: macronutrients vs. micronutrients.

Water - H2O - every organism needs it to metabolize, and thus to grow and reproduce

Carbohydrates - sugars and sugar-like stuff, combinations of C6H12O6 units:

• Monosaccharides: glucose, fructose, galactose
• Disaccharides: sucrose (glucose + fructose), lactose (glucose + galactose), maltose (2 glucose)
• Polysaccharides: starch, cellulose (chains of glucose)

They are often different by some of their structure being mirror images. Glucose and galactose are "aldohexoses", having a mirror-image difference in the asymmetry of one of their carbon atoms. Fructose is a "ketohexose". Starch and cellulose have mirror-image asymmetries in how their glucose units are bonded, but starch is much more easily digestible than cellulose.

Though we cannot digest cellulose, its presence, as fiber, helps us digest our food.

Fats - mostly triglycerides, three "fatty acids" attached to a glycerol molecule. Fatty acids are straight-chain mostly-saturated hydrocarbons with a carboxyl group -COOH at one end, the acid part. They are related to acetic acid, the vinegar acid CH3COOH though they are much longer.

Some of them are "essential" fatty acids, which we cannot make for themselves:

• Alpha-linolenic acid: 18 carbons, double bonds starting at 3, 6, 9 from the HC or "omega" end -- an omega-3 fatty acid.
• Linoleic acid: 18 carbons, double bonds starting at 6, 9 from the HC or "omega" end -- an omega-6 fatty acid.

The double bonds make them unsaturated, and also give them a lower melting point. Fat with less-saturated fatty acids can be liquid at room temperature, making it an oil.

Proteins - chains of "amino acids" ("peptides") and combinations of them, sometimes with extra stuff added on, like heme for hemoglobin.

There are 20 protein-forming amino acids, AA's that are used by every well-studied organism on this planet, and 10 of them are "essential", meaning that we cannot make them for ourselves. There are two pairs of them, with us being able to make one pair member from the other. That means effectively 8 sets of EAA's.

These amino acids have a central carbon atom, with a hydrogen, a carboxylic-acid group -COOH, an amino group -NH2, and an extra group that varies, often written -R for radical.

The smallest of them, glycine, has -H for -R, and is thus symmetric. All the others have a characteristic asymmetry in that central carbon atom called L. Some organisms make and use the mirror images of some of them, "D" amino acids, however.

Vitamins - biological molecules that we need in very small quantities, but that we nevertheless need because we cannot make them ourselves, or at least make enough of them ourselves.

Water-soluble vitamins:

• B1: thiamine
• B2: riboflavin
• B3: niacin
• B5: pantothenic acid
• B6: pyridoxine, ...
• B7: biotin
• B9: folic acid / folate
• B12: cobalamin
• Choline
• C: ascorbic acid

Fat-soluble vitamins:

• A: retinols, carotenes, ...
• D: calciferol
• E: tocopherols, tocotrienols
• K: quinones

Minerals - inorganic nutrients. They can be enzyme parts (coenzymes), structural materials, and fluid constituents (electrolytes)

Needed in relatively large quantities are Ca, Cl, Mg, P (as PO4), K, Na

Needed in relatively small quantities are Co, Cu, Cr, I, Fe, Mn, Mo, Se, Zn

There are others that are possibly necessary in very small quantities, but that has not been confirmed for them, and some of them may essentially be impurities.  Composition of the human body lists many of the stable and longer-lived elements that have been found in our bodies, and many of them are in very tiny amounts.

 

[Jokodo]

What I have read is that for some of those unconfirmed essential nutrients, while there are no recorded cases of humans suffering a clinical deficiency have been recorded and likely never will because feeding a human on a diet artificially empoverished of an element ubiquitous enough in the environment that a lack of it isn't going to just happen, for long enough to see long term effects or effects only becoming relevant at puberty, isn't feasible not just for moral but also for logistical reasons, there is good evidence in the form of rodent studies that they are in fact essential minerals for at least some mammals. Mammalian physiology and biochemistry being a uniform as it is at that level, this should count as evidence that they are also essential to humans.

I'd have to dig up the details, but I seem to remember Borium and Arsenic and possibly lead being mentioned as hit candidates for that status on the paper I have in mind.

So maybe the only real difference between the "poison" arsenic and the valuable nutrient selenium is that four selenium, ambient concentrations tend to be at the lower end of the range of what's good for as and often below so deficiencies are common and overdoses virtually unheard of, while for arsenic, they tend to be at the high end of that range and not infrequently above, so that poisonings are common and deficiencies unheard of - while the actual range might in fact be similar for both!

 

[lpetrich]

 The dose makes the poison - just about everything essential we can have an overdose of.

Overdose of water?  Hyponatremia -- too little sodium in the blood. Our kidneys are normally good at excreting extra water, but they can become overloaded by us drinking large quantities of it. This can be a problem if one has done a lot of exercise and athletics, and one wants to replace the water lost as sweat.

Overdose of oxygen?  Oxygen toxicity and  Breathing gas - the maximum safe partial pressure of O2 for us is about 1.6 bar. Our planet's atmosphere at sea level has an O2 partial pressure of 0.2 bar. 1 atmosphere = 1.013 bar.

Nitrogen is an essential part of proteins and nucleic acids, but nitrogen gas - N2 - is close to inert.  Nitrogen narcosis sets in at partial pressures more than 4 bar. In the sea-level atmosphere, it's 0.8 bar.

Can You Overdose on Vitamins? - yes, though in most cases, one has to take a lot of supplements to do so.

An exception is vitamin-A poisoning:  Hypervitaminosis A - one can get lethal doses from "normal" eating portions of some animals' livers, like 500 grams of polar-bear liver.

One can also overdose on minerals.  Iron poisoning and  Iron overload

 

[lpetrich]

Nutrient Requirements of the Laboratory Rat - Nutrient Requirements of Laboratory Animals - NCBI Bookshelf - very close to human ones, with the same essential fatty acids, essential amino acids, vitamins, and minerals, except that rats can make their own vitamin C.

 Essential amino acid and  Essential fatty acid and  Vitamin and  Mineral (nutrient)

dog_nutrition_final_fix.pdf - same essential amino acids, same essential fatty acids, same vitamins except for vitamin C, same minerals.

Cat Nutrition: Guide to Cat Food Nutrients | PetMD - they need arginine, "conditionally essential" for us, and taurine, but not vitamin C. We can make our own  Taurine as can many other species.

Loss of the ability to make vitamin C has happened several times:  Vitamin C - The Genetics of Vitamin C Loss in Vertebrates - PMC - from the GLO biosynthesis gene being broken in various ways, with the pattern of breakage being consistent: simians having one pattern and guinea pigs another pattern.

 

[thebeave]

 The dose makes the poison - just about everything essential we can have an overdose of.

Overdose of water?  Hyponatremia -- too little sodium in the blood. Our kidneys are normally good at excreting extra water, but they can become overloaded by us drinking large quantities of it. This can be a problem if one has done a lot of exercise and athletics, and one wants to replace the water lost as sweat.

Overdose of oxygen?  Oxygen toxicity and  Breathing gas - the maximum safe partial pressure of O2 for us is about 1.6 bar. Our planet's atmosphere at sea level has an O2 partial pressure of 0.2 bar. 1 atmosphere = 1.013 bar.

Nitrogen is an essential part of proteins and nucleic acids, but nitrogen gas - N2 - is close to inert.  Nitrogen narcosis sets in at partial pressures more than 4 bar. In the sea-level atmosphere, it's 0.8 bar.

Can You Overdose on Vitamins? - yes, though in most cases, one has to take a lot of supplements to do so.

An exception is vitamin-A poisoning:  Hypervitaminosis A - one can get lethal doses from "normal" eating portions of some animals' livers, like 500 grams of polar-bear liver.

One can also overdose on minerals.  Iron poisoning and  Iron overload

Note to self: Cut back on the polar-bear liver.

 

[Elixir]

Note to self: Cut back on the polar-bear liver.

Just don’t exceed 499 grams.

 

[thebeave]

Note to self: Cut back on the polar-bear liver.

Just don’t exceed 499 grams.

Good catch! I somehow skimmed over that part.

 

[lpetrich]

Going further, I've found Feeding and Management Practices in Poultry - Poultry - Merck Veterinary Manual - the same nutritional requirements there also.

Even further: Nutrition and health of aquaculture fish - 4335-English.pdf and Understanding Fish Nutrition, Feeds, and Feeding: FST-269.pdf and An overview on significance of fish nutrition in aquaculture industry | International Journal of Fisheries and Aquatic Studies and Nutritional Diseases of Fish in Aquaculture and Their Management: A Review

Mentioning arginine as an additional essential amino acid - it's an essential one for some other species I've researched, and it's "conditionally essential" for us, so its biosynthesis can be inadequate.

Also,  Inositol as an additional water-soluble vitamin. We can make our own, however.

This covers all the bony vertebrates.

Elasmobranch Husbandry Manual II: Recent Advances in the Care of Sharks, Rays and their Relatives -- notes vitamin and mineral deficiencies that sharks in aquariums can have.

So we have a little bit of data on the remaining jawed vertebrates. But then again, detailed nutritional needs can be hard to research. One needs to feed one's subjects good amounts of all but one nutrient and watch what happens.

 

[steve_bank]

Prescience people figured out which foods to combine.

Rice and beans provide a complete protein. Rice, beans, and corn supplemented with a little chicken or beef are a traditional diet.

Rice and beans wrapped in a corn tortilla.

Both are easy to grow, plentiful, and filling. The combination of beans and rice creates a complete protein. Beans alone and rice alone both lack certain essential amino acids. If eaten together, however, each contributes what the other is missing to form a complete protein.

Do rice and corn make a complete protein?

Every time legumes like beans, lentils, and peanuts are combined with grains like wheat, rice, and corn, a complete protein is born.

One of my regular breakfasts is scrambled eggs with rice and beans. Protein.

My basic diet is rice and beans with chicken, pork, and beef but not every day for meat. Plus vegetables.

My doctors say with a varied diet you should get all you need, but I take a daily generic multi vitamin mineral supplement. Cheap insurance.

 

[lpetrich]

Looking even further,

Nutrient Requirements of Penaeid Shrimp - Nutrient-Requirements-of-Penaeid-Shrimp.pdf - mentions essential fatty acids but says that there is not much research on vitamin and mineral needs

The laboratory fruit fly:

Nutritional Requirements of Axenically Cultured Drosophila Melanogaster Adults | Journal of Experimental Biology | The Company of Biologists and The Quantitative Nutritional Requirements of Drosophila Melanogaster | Journal of Experimental Biology | The Company of Biologists - the same essential amino acids, vitamins and minerals, as far as it was possible to research their nutritional needs.

The first one: "Omission tests showed that casein, the B vitamins (other than B12 and biotin) K and Mg were essential for normal ovary development." and "The ten ‘essential’ amino acids were all found necessary for egg production but arginine, histidine and methiohine were apparently synthesized, although at an inadequate rate"

The second one: thiamine, riboflavin, niacin, pantothenate, pyridoxine, biotin, folate, choline. Vitamin B12 is iffy, and vitamin C is unnecessary.

Ten generations of Drosophila melanogaster reared axenically on a fatty acid‐free holidic diet - Rapport - 1983 - Archives of Insect Biochemistry and Physiology - Wiley Online Library - "Wild-type Drosophila melanogaster were axenically raised on a completely synthetic fatty acid-free diet for at least ten consecutive generations, confirming that these insects do not require dietary polyunsaturated fatty acids." - they can make their own "essential fatty acids"

The mealworm beetle:

THE NUTRITIVE REQUIREMENTS OF TENEBRIO MOLITOR LARVAE | The Biological Bulletin: Vol 83, No 3 and Protein nutrition of Tenebrio molitor, L. 3. Replacement of casein by a mixture of 10 or 9 amino acids. - the same essential amino acids, several vitamins

First one: Tthiamine, riboflavin, niacin, pantothenate, pyridoxine necessary, A, C, D, E, K, choline no effect.

INSECT NUTRITION - TRAGER - 1947 - Biological Reviews - Wiley Online Library

They need only one fat-soluble nutrient: cholesterol. Vitamin D cannot substitute for it. However, they need most of the water-soluble ones, mostly B vitamins. "... the necessity of one or more for normal growth has already been demonstrated for species of the orders Hemiptera, Coleoptera, Lepidoptera, and Diptera." ("true bugs", beetles, butterflies and moths, flies and mosquitoes)

"Various salts are essential constituents of the diet for most insects." - minerals.

 

[lpetrich]

Flies and beetles are four-stage insects, so I decided to look for three-stage ones.

THE NUTRITIONAL REQUIREMENTS OF GRASSHOPPERS: I. REARING OF THE GRASSHOPPER, MELANOPLUS BIVITTATUS (SAY), ON A COMPLETELY DEFINED SYNTHETIC DIET AND SOME EFFECTS OF DIFFERENT CONCENTRATIONS OF B-VITAMIN MIXTURE, LINOLEIC ACID, AND β-CAROTENE - they need B vitamins but not the others.

I found several papers on cockroach nutrition, but they are all paywalled. Nutrition Studies with the Cockroach (Blattella germanica) | Physiological Zoology: Vol 10, No 1 and Vitamin Requirements of the Cockroach Blatella Germanica (L.)1 | Annals of the Entomological Society of America | Oxford Academic and Growth Studies with the Cockroach, Periplaneta Americana (Linn.), Fed Vitamin-Deficient Diets Substituted with Corresponding Anti-Vitamins2 | Annals of the Entomological Society of America | Oxford Academic and The Nutritional Requirements of Blattela germanica | Physiological Zoology: Vol 11, No 1

The B vitamin nutrition of insects: the contributions of diet, microbiome and horizontally acquired genes - ScienceDirect

Insects generally cannot synthesize eight B vitamins that function as co-enzymes in various required enzymatic reactions. Most insects derive their B vitamin requirements from the diet, microbial symbionts, or a combination of these complementary sources. Exceptionally, the genomes of a few insects bear genes in vitamin B5 (pantothenate) and B7 (biotin) synthesis, horizontally acquired from bacteria.

Some insects, like aphids, have microbes residing in them that make nutritional supplements for them. That enables aphids to live on plant sap, something that is junk food for aphids. I call it that because of its very limited nutritional value for aphids. In fact, aphids excrete most of its water and sugar, as honeydew. Some ants like to drink this honeydew from aphids, and these ants protect these aphids, thus doing a sort of dairy farming.

So that covers all the insects that can fold their wings against their bodies (Neoptera).

Insects branched off from other crustaceans in the early Paleozoic, thus making them land shrimp.

So I've covered Deuterostomia (vertebrates) and Ecdysozoa (arthropods), so I turned to Lophotrochozoa. I looked for stuff on nutrition of domestic snails (escargot), but without success.

That covers all of Bilateria: Protostomia (Ecdysozoa, Lophotrochozoa) and Deuterostomia, even if very patchily.

So the ancestral bilaterian needed the essential amino acids and most B vitamins.

 

[lpetrich]

Looking outside the animal kingdom for more heterotrophs, I turned to fungi.

Nutritional requirements of a Saccharomyces cerevisiae starter culture used in the elaboration of wine from orange - ("Sugar fungus of beer") that's common yeast, used in making bread rise and in making alcoholic drinks by fermentation of sugar to alcohol. It's also used as a model system in a lot of lab experiments.

It needs thiamine, pantothenate, pyridoxine, biotin -- only four vitamins

Neurospora crassa (red bread mold) - Neurospora crassa - an overview | ScienceDirect Topics

Neurospora grows at a prodigious rate – the mycelium advances at ∼4 mm h−1 in a reasonably warm (e.g., 32 °C) environment if given some sugar, simple nutrients, and one vitamin (biotin).

So it can use a single organic carbon source for everything except biotin, with inorganic sources for the other elements.

Some heterotrophic bacteria go one better, being able to make *everything* from a single organic carbon source and inorganic sources. Like this: Sugar Synthesis from CO2 in Escherichia coli - PIIS0092867416306687.pdf - describes raising Escherichia coli bacteria on an inorganic medium with one organic carbon source: pyruvic acid.

 

[lpetrich]

Wouldn't it be great to have the nutritional needs of some bacteria? We could eat the junkiest of junk food and still be well-nourished.

Also, let's say we were preparing nutritional supplements for various species. A chimp would use ours without any changes, as would a guinea pig. A rat or a dog will pass on the vitamin C, and a cat will also, but will want taurine.

An insect would only want B vitamins, a yeast only four of them, and a mold only one of them. What a limited business, making only biotin. Some bacteria, like Escherichia coli and various Pseudomonas species, need no supplements at all. One would have to advertise one's supplements as helping to speed up growth.

 

[Loren Pechtel]

So maybe the only real difference between the "poison" arsenic and the valuable nutrient selenium is that four selenium, ambient concentrations tend to be at the lower end of the range of what's good for as and often below so deficiencies are common and overdoses virtually unheard of, while for arsenic, they tend to be at the high end of that range and not infrequently above, so that poisonings are common and deficiencies unheard of - while the actual range might in fact be similar for both!

Wouldn't surprise me one bit. My body is so messed up about food that I have to pay attention to such things. It's quite possible to go over the maximum accepted arsenic just from eating stuff grown in areas where they used to use arsenic pesticide.

 

[Loren Pechtel]

 The dose makes the poison - just about everything essential we can have an overdose of.

Why do you say "just about"? What is not possible to overdose on? And for that matter is there anything non-essential that doesn't have a toxic level? That's one of the reasons they're looking at the possibility of liquid breathing systems--all materials that are gasses by our body's definition are toxic in sufficient amounts. Nitrogen is simply the one we are most likely to actually get into trouble with, but the entire space has been explored--so long as it's not done too fast our body doesn't seem to care about pressure, but we eventually hit a limit where there's nothing they can put in the diver's tank that won't be a problem.

 

[steve_bank]

Too much or too little sodium is not good.

Water intoxication is a rare phenomenon that occurs due to an excessive intake of water, and when the amount of water intake exceeds that of water excretion in the kidney. As a result, the sodium concentration in the blood is diluted, and hyponatremia develops.

Mega does of some vitamins can causee problems.

Too much of the water soluble Vitamin B6, for instance, can lead to nerve damage. Vitamin C in excess will lead to stomach upset, and too much Vitamin D could cause kidney damage amongst other things.

 

[bilby]

Too much or too little sodium is not good.

Too much or too little ANYTHING is not good.

Too little of some things is tolerable, as long as you can synthesise or substitute that thing. But as a general rule, bigger or smaller amounts than is typical, in the wide range of human long-term diets, is going to be uncomfortable, if not fatal.

Humans are fragile creatures, like all organisms that evolved in an environment where complex nutrients were readily available.

If I can out-compete my contemporaries, by dropping ascorbate synthesis in favour of obtaining it from my diet, then that's obviously the winning evolutionary strategy - right up until my environment changes to an eighteenth century transoceanic sailing ship, which has no citrus fruits or sauerkraut on board.

 

[lpetrich]

 The dose makes the poison - just about everything essential we can have an overdose of.

Why do you say "just about"? What is not possible to overdose on? ...

I was trying to be cautious.

 

[lpetrich]

Prescience people figured out which foods to combine.

Rice and beans provide a complete protein. Rice, beans, and corn supplemented with a little chicken or beef are a traditional diet.

10 Foods High in Essential Amino Acids

• Complete: Red meat, Chicken, Fish, Seafood, Eggs, Milk, Cheese, Yogurt, Quinoa, Chia seeds, Tofu
• Incomplete: Grains, Nuts, Seeds, Beans, Legumes, Fruits, Vegetables

13 Nearly Complete Protein Sources for Vegetarians and Vegans

• Single items: quinoa, soybeans, amaranth, buckwheat, spirulina, hemp seeds, chia seeds, yeast
• Multiple items: rice & beans, pits & hummus, peanut butter sandwich

The multiple ones are all (cereal grain) + (legume), and they work by each one filling in for what the other one is short on. The grains are short on lysine and the legumes short on methionine + cysteine.

 Essential amino acid and  Protein quality and  Protein (nutrient) and  Protein Digestibility Corrected Amino Acid Score and  Digestible Indispensable Amino Acid Score and Proportions of amino acids in selected foods across food groups. ... | Download Scientific Diagram -- hard for me to find any good comprehensive database of amino-acid contents.

Animal flesh, across all of Bilateria, and animal products, milk and eggs, are all complete. Fungi are somewhat like legumes in being short on Met+Cys, as is Chlorella green alga. Sprulina, a cyanobacterium (blue-green "alga"), seems to be complete.

Quinoa, amaranth, and buckwheat food items are all seeds of their plants, as are cereal grains and legume food items and nuts. We also eat other parts of plants: tubers (expanded roots), stems, leaves, and seed containers.

 

[lpetrich]

The genome revolution has made available an enormous quantity of genetic data, so one can check on whether some organism has some recognizable genes for biosynthesis.

KEGG: Kyoto Encyclopedia of Genes and Genomes has KEGG PATHWAY Database with known pathway genes for a large number of organisms. The pathways cover a wide range.

Metabolism covers biosynthesis and breakdown of sugars, fatty acids, amino acids, vitamins, terpenes, and a variety of others.

Also has genetic informational processing, environmental informational processing, cellular processes, organism development, etc.

So I'll look in it.