Wednesday, March 29, 2023

Nutrients that work together

A healthy body needs hundreds of nutrients for its proper functioning. Most of them are acquired through the foods we eat. The body is able to manufacture the remaining few.

Types of nutrients

These nutrients broadly fall in 9 different categories:

  1. Carbohydrates
  2. Proteins (all proteins are made from combinations of 22 basic amino acids)
  3. Fats, such as omega–3 (ALA, DHA, etc) and omega–6 (ARA, GLA, etc)
  4. Vitamins, such as vitamin A and vitamin D
  5. Minerals, such as calcium and magnesium
  6. Trace elements, such as zinc, copper, and chromium
  7. Fibers, such as water–soluble (inulin, guar gum, pectin, etc) and semi–soluble (psyllium)
  8. Phytonutrients, such as polyphenols, catechins, isoflavones, saponins, and terpenes
  9. Water

For our bodies to function, nutrients are needed in different proportions, and at various stages. But the most interesting part: Many nutrients work together.

Purpose of this article

This article is written with three aims in mind:

How nutrients combine

First, the article will explain how commonly required nutrients work in concert with one another. It will also mention how they should be combined and consumed for optimal health.

How nutrients are different from medicines

Second, this article will highlight how nutrients are completely different from medicines. It will explain why nutrients should never be evaluated in isolation, unlike medicines. If you cannot hold your patience for this, jump to the end of this article, to read: Discussion on this subject.

How our body is not perfect

Third, and a subtle, purpose of this article is to point out that the complex mechanisms by which nutrients work in our body are not necessarily perfect. People assume that if the body does something, it must be the ideal way. After all, millions of years of evolution would have refined that mechanism. That is not true, as you will read about inefficiencies in the body functioning. We are, thus, a work in progress.

Recommended allowances (RDA) of nutrients

Currently, there is a lot of debate about optimum amounts of nutrients a body needs. Various organisations have come up with guidelines for that.

A nutrient is needed in varying amounts for different ages, gender, and even life–stages. For example, in childhood and very old age, one would not need nutrients that help in reproductive health. Similarly, women would need higher levels of calcium than men, and in pregnancy, the need would go even higher.

If you get more granular, your ethnicity, lifestyle, and current medical conditions could also affect the nutrient requirement. For example, people with certain heart conditions are advised a higher amount of fish oil consumption compared to those who have no heart disease.

Read on this website: Recommended dietary allowances of various nutrients.

Nutrients work together

While there is science and studies behind the RDA numbers published, there is a big missing ingredient: Nutrients interact with one another. Their actions may be enhanced in the presence of another. Similarly, low intake of a nutrient might reduce efficacy of another, needing more quantity of it. On the other hand, some nutrients act against each other, reducing their respective strengths.

Thus, quoting an RDA number for a nutrient, in isolation, can be misleading. But we will leave that for another article.

In this article, let us study various nutrients that work better (or worse) together. Of course, it is far from a complete list. But, it will help you understand the complexities of evaluating nutrients, in isolation.

Calcium and vitamin D

One can write a whole book about this combination. But, in the simplest form, the body needs vitamin D to absorb calcium.

On its own, calcium is needed for stronger bones and teeth, nerve transmission, muscle contractions and blood clotting.

Vitamin D has many benefits throughout the body. It can also help in blood pressure, colon polyps, multiple sclerosis, etc.

Vitamin D has various forms. It has an active form called Calcitriol, which is formed by the kidneys. Calcitriol is needed for absorption of calcium from food in your intestines.

In certain conditions, such as damaged kidneys or vitamin D deficiency, the body does not make enough calcitriol. If sufficient calcitriol is not present, your body will not absorb the calcium from the food. This will happen even if you eat a lot of calcium–rich foods. In such situations, your body will pull calcium out of the bones for the essential needs. This leads to weaker bones.

This calcium—vitamin D interaction is important to understand, especially, in medical conditions such as osteoporosis (brittle bones), osteomalacia (softening of bones), kidney disease (kidneys make calcitriol), and hyperparathyroidism (parathyroid hormone causes bones to release calcium into blood).

Calcium is found in dairy products, oranges, figs, broccoli, and collard greens. Vitamin D comes in egg yolks, and fish such as salmon and tuna. Many developed countries have vitamin D–fortified beverages such as milk, soy milk, and orange juice.

Different foods contain calcium and vitamin D. There are very few common food sources of the two.

Both food sources don’t need to be eaten together.

If you are taking a calcium supplement, ensure it also has vitamin D.

Iron and Vitamin C

Iron is available in two forms in our foods: heme iron and non–heme iron. The difference comes from how iron is bound as a molecule inside that food item.

Heme iron

Heme iron comes from animal sources. The iron, here, is bound as haemoglobin and myoglobin. Haemoglobin is an oxygen– and iron–carrying molecule in the blood. Myoglobin is an oxygen– and iron–carrying molecule in the muscles.

Heme iron is found in meat, fish and shellfish. But, only about half the iron in those sources is of heme type.

Non–heme iron

Non–heme iron comes from plant sources. The iron, here, is bound mostly in ferric form, and a bit in ferrous form (ignore if this is too technical for you).

Non-heme iron is found in grains, beans, nuts, seeds, fruits, and vegetables. The iron in eggs and dairy products is completely non–heme. Half the iron content in the meats, fish, and shellfish is also of non–heme type. So, about 80–90% of iron we eat is of non–heme variety.

Iron absorption in the body

Iron is absorbed in the early parts of the intestine. For that, the iron needs to be in the soluble form. What complicates the matter is, just before the region where iron is absorbed, comes the stomach. Stomach is acidic in pH and intestine, where iron is absorbed, is alkaline in pH. As dietary iron moves from an acidic to an alkaline environment, it is very difficult to keep it in soluble form if it is inorganic in nature, as is the non–heme iron.

Heme iron is in organic form. It is kept in the soluble form by certain enzymes secreted by the pancreas. After it gets absorbed in the intestine, it gets converted to non–heme iron and gets used by the body. Since it is easy to keep heme iron soluble, its absorption levels are high — about 25% — of the consumed amount.

Non–heme iron is absorbed in the same parts of the intestine as the heme iron. However, many dietary ingredients retain or convert non–heme iron in insoluble form. The body cannot absorb such iron. The absorption is typically 2–5%, as a result — much lower than that of heme iron.

Foods that block iron absorption

The foods that inhibit non–heme iron absorption are caffeine (coffee), tannins (tea), calcium (any calcium–rich food), phytates (some excellent foods such as almonds, walnuts, and rice bran), oxalates (some good plants such as spinach, beets, and nuts), polyphenols (fruits, vegetables, legumes, tea, coffee, and wine), phosphates (dairy products, meat, lentils and nuts), and carbonates (food products fortified with calcium carbonate).

Many of these food sources are excellent for health. One is often encouraged to consume them for various health benefits. However, remember that they inhibit the absorption of non–heme iron if eaten together with non–heme iron sources. Phytates are particularly bad because they reduce non–heme iron absorption drastically.

Vitamin C enhances iron absorption

Walks in vitamin C, in this situation. It keeps the non–heme iron in soluble, and so absorbable, form as it enters the intestines. Through various mechanisms, it increases the absorption, and then assimilation, of iron in the body.

Vitamin C reverses the effect of all the food ingredients that inhibit non–heme iron absorption. In the presence of vitamin C, the non–heme iron absorption in the body can rise to nearly 20%, almost on par with heme iron absorption levels.

Vitamin A and carotenes increase iron absorption

While we are at it, it helps to know that vitamin A and beta–carotenes also help increase absorption of non–heme iron.

Vitamin A and beta-carotenes are found in carrots, spinach, kale, squash, red peppers, oranges, peaches, and sweet potatoes.

Fish, meat, and shellfish increase non–heme iron absorption

While meat, fish and shellfish are excellent source of heme iron, they are also found to increase the absorption of non–heme iron from plant sources, if eaten simultaneously. Just like vitamin C, they are also found to overcome the negative effects of tannins, phytates, and polyphenols on iron absorption.

Excess iron and its problems

If the body gets excess iron, it has no way of eliminating it, except through blood loss. And, the body cannot trigger this blood loss, on its own. So, it stores the excess iron in the joints, liver, heart and pancreas. This damages those organs.

Iron is a pro–oxidant (opposite of an anti–oxidant). So it can cause what is called oxidative stress. Therefore, one has to be careful about iron consumption and not go overboard with it.

There is another direct problem with heme iron, which leads to conditions such as heart disease, stroke, gastrointestinal problems, and certain types of cancers.

In other words, heme iron gets well absorbed by the body but it has its problems, including that of high iron intake. Non–heme iron does not get well absorbed by the body in the presence of healthy food items (so, avoiding them is not a solution). But vitamin C solves this issue.

Taking non–heme iron along with vitamin C is the best way to take iron.

You need to take both of them together in the same meal.

Don’t have tea, coffee, and milk at, or around the same time as, iron–rich foods.s

Fish, meat, and shellfish are great source of absorbable iron. They also help in increasing absorption of poorly absorbed iron forms.

If you are taking an iron supplement with non–heme iron (plant–based), choose one that also contains vitamin C. Take it on empty stomach in the morning.

Phew! So many permutations and combinations. I pity those people who want a pulp advice for: “should I take more iron?”

Sodium and Potassium

Sodium and potassium work together to help in energy production, fluid balance, kidney function, bone strengthening, nerve signal conduction, and muscle contraction.

Most people consume more sodium than they need, in the form of salt. Excess sodium interferes with the natural ability of the blood vessels to relax and expand. This increases blood pressure, which increases the chances of having a stroke or a heart attack.

However, potassium helps the kidneys excrete sodium. Unfortunately, during the process of sodium excretion (which is good), potassium also needs to be eliminated (which is bad) in the urine.

So, if potassium intake is low, the body prevents potassium excretion, which in turn prevents sodium excretion. On the other hand, many studies have shown a connection between high potassium intake and lower, healthier blood pressures.

Read here about body’s delicate balance of sodium and potassium.

Foods high in potassium are bananas, oranges, apricots, prunes, raisins, dates, potatoes, mushrooms, peas, cucumbers, spinach and broccoli. Foods high in sodium are cured or canned meat, cold cuts, ham, sausages, pizza, burritos, salted nuts, etc. Sodium is a great preservative and so is added to many canned foods. Fresh foods contain very little sodium.

Increase your intake of potassium–rich foods and reduce your intake of sodium–rich foods.

Calcium and magnesium

Calcium and magnesium have many important functions in the body individually. However, they work jointly to perform many tasks such as:

  • Contraction and relaxation of muscles
  • Contraction and relaxation of blood capillaries
  • Maintenance of cell membranes
  • Building strong bones and teeth

Thus, having one in sufficient quantity, and the other in inadequate amount, makes them incapable of performing the above duties. In fact, deficiency of magnesium, with adequate calcium intake is a recipe for heart disease and kidney stones. Read: Too little magnesium can affect heart health.

Also, it appears that the ratio of calcium to magnesium is important. A ratio of 2 parts calcium to 1 part magnesium by weight looks reasonable.

Good sources of calcium are dairy products, figs, oranges, broccoli and collard greens. Good sources of magnesium are green leafy vegetables such as spinach and kale, legumes such as chickpeas, kidney beans, and black beans, fruits such as bananas, figs, and raspberries, vegetables such as broccoli, green beans, asparagus, brussels sprouts, peas, and cabbage, fish such as salmon, mackerel, and tuna, nuts and seeds.

Note that while you need more than 1000 mg of calcium a day, your body cannot absorb more than 500 mg of calcium at any given time. So it is best to split the daily calcium intake over 3 to 4 rounds of consumption.

Interestingly, if you take calcium or magnesium in quantities of more than 250 mg at a time, they compete with each other in the intestines for absorption. So it is good to stagger calcium and magnesium intake more than one hour apart.

Take adequate quantities of calcium and magnesium.

They need not be taken together. But if you do, don’t take more than 250 mg at a time of either.

If you are taking a calcium supplement (with vitamin D), make sure you also take magnesium in the ratio of about 2 parts calcium : 1 part magnesium. The same supplement need not have magnesium; you can take two separate ones.

Don’t take calcium more than 500 mg at a time in food or supplement form. Stagger the calcium consumption through the day.

250 mg calcium at a time is even more preferred, if you are going to also take magnesium with it, either in food or through a supplement.

Zinc and Copper

Zinc has a role to play in immunity, learning and memory formation, wound healing, male fertility, and age–related macular degeneration.

Copper is required for heart health, immunity, nerve conduction, collagen production, and preventing osteoporosis.

Copper and zinc are both absorbed in the small intestines. However, zinc absorption reduces copper absorption in the intestines.

Inside the body also, zinc and copper compete for the same binding sites, reducing each other’s efficacy.

Thus, if one takes high dose zinc supplements for longer than 3 months, one is likely to face symptoms of copper deficiency.

Most food sources of zinc are also the food sources for copper. So you cannot avoid the zinc and copper competition in the intestines as well as in the body.

Zinc reduces the absorption and the efficacy of copper.

You cannot micro–manage their dietary intakes. Just be aware of the above, especially if you are taking zinc supplements of more than 50 mg a day.

If you love reading arcane stuff, read here: Various mechanisms in the body by which minerals are absorbed.

Caution with minerals

Keep in mind that many minerals compete with one another for absorption and inside the body. So one cannot talk about adequate quantities of any of them in isolation.

None of them is more important than the other. Each of them has a role. So they need to be in proper balance or ratio. Keep this in mind, especially if you decide to take large quantity of any specific mineral through food or supplements.

As a rule of thumb, if you take any supplement, which gives you up to the recommended dietary allowance (RDA) of any mineral, you are safe.

Multi–mineral supplements containing RDAs of many minerals are generally safe.

Take professional advice before going for high–dose supplements of individual minerals.

Various B–vitamins

The B-complex group consists of eight vitamins, which are similar in chemical structure. They are B–1 (thiamine), B–2 (riboflavin), B–3 (niacin), B–5 (pantothenic acid), B–6 (pyridoxine), B–7 (biotin), B–9 (folate or folic acid), and B–12 (cobalamine). They are found in a limited number of food sources such as dairy products and chicken.

Vitamins B–1 and B–2

Vitamins B–1 and B–2 work together to support the health of muscles, nerves and the heart.

Vitamins B–3 and B–6

Vitamins B–3 and B–6 work together to maintain the nervous system.

Vitamins B–5 and B–7

Vitamin B–7 supports the work of coenzyme A, a derivative of vitamin B–5. Coenzyme A is needed in making cholesterol, sex hormones, stress hormones such as cortisol and adrenaline, the sleep hormone melatonin, and the neurotransmitter acetylcholine.

Vitamins B–9 and B–12

Vitamin B–12 helps the body absorb vitamin B–9, and the two work together to help cell division and replication. The cells that line the stomach walls and those of the hair follicle divide and replicate often. Their functionality benefits from the two vitamins.

Vitamins B–9 and B–12 also work together to produce blood cells.

People who eat poorly or drink too much alcohol may have vitamin B–9 deficiencies. People who don’t eat meat, fish or dairy products may have vitamin B–12 deficiencies.

Vitamin B–9 is found in leafy green vegetables, beans, and other legumes. Vitamin B–12 is found in meat, eggs, and milk.

Vitamins B–6, B–9, and B–12

One byproduct of protein digestion is homocysteine, which in high levels, is thought to damage inner linings of arteries, leading to heart disease and stroke. Vitamins B–6, B–9, and B–12, together, help reduce homocysteine. They cannot do that individually.

Always consume a full–spectrum of all eight B–vitamins, either through foods or through supplements.

Discuss the above points with your doctor, if he advises just one of the B–vitamins, such as a vitamin B–12 injection or a vitamin B–9 (folic acid) tablet.

Vitamins A, D, E, K and fat

Vitamins A, D, E and K are all fat soluble vitamins. They are better absorbed if consumed with little fat.

Even these vitamins compete for absorption amongst themselves:

  • The absorption of vitamin K reduces significantly if vitamins A, D, and E are also present.
  • Vitamin A reduces the absorption of vitamins D, E, and K.
  • But, vitamins D and K do not reduce the absorption of vitamin A.
  • Vitamin E increases the absorption of vitamin A.

Go figure!

If you are taking any of the fat–soluble vitamins through foods, or supplements, take them with a bit of healthy oil, such as olive oil or fish oil.

Avoid taking vitamin K–rich foods, or vitamin K supplements, along with vitamins A, D, and E.

Here are some guidelines on how to take vitamins and minerals for proper absorption.

Omega–3 and omega–6 oils

This subject could easily be worthy of another thick book. But let me just highlight a few points.

What are omega–3 and omega–6 oils

Fats, in general, are used for energy storage by the body. However, some special types of fats, called omega–3 and omega–6 fats, also play a role in various body functions, such as cell membrane formation, inflammation, enzyme production, and blood clotting.

Our bodies cannot make them and so they have to be taken from outside. If we can not get enough of them, we may develop medical problems.

Omega–3 versus omega–6 conflict

Omega–3 oils are anti–inflammatory in nature (which is considered good). Many of the omega–6 oils are pro–inflammatory (which is considered bad).

In fact, some omega–6 oils compete for the same enzymes that omega–3 oils use in reducing inflammation. So, not only do omega–6 oils cause extra inflammation, they also reduce the inflammation–lowering capacity of omega–3 oils. A clear conflict!

Thousands of years ago, our ancestors used to eat omega–6 and omega–3 in the ratio 1:1. That means, we were taking omega–6 oils and omega–3 oils in similar quantities. You can roughly say that the two were balancing out their pro–inflammatory and anti–inflammatory actions, keeping our ancestors healthy.

Nowadays, their ratio in our diets is about 15:1. Thus, we are effectively taking 15 times more omega–6 oils than omega–3 oils. In a way, we are consuming 15 times more pro–inflammatory stuff than anti–inflammatory one, when it comes to these two types of oils.

Some experts attribute the modern epidemics of chronic lifestyle disorders, such as diabetes, heart disease, memory loss, and osteoarthritis to this excess inflammatory oil intake. Read here: how to optimise your omega–6 to omega–3 ratio?

Balancing omega–3 and omega–6 intake

Omega–3 oils are found in fatty fish such as salmon, mackerel, and anchovies, and plant–based sources such as flaxseeds and walnuts.

Men are advised 1600 mg of omega–3 oils a day; while women are advised 1100 mg of them. Most people don’t get enough of omega–3 oils through food, to counteract the effect of omega–6 vegetable oils.

Omega–6 oils are found in poultry, eggs, nuts, cereals, and most vegetable oils.

Reduce your intake of some omega–6 vegetable oils such as sunflower oil, corn oil, soybean oil, and cottonseed oil. Increase your intake of omega–3 oils such as fish oils.

If you cannot reduce your intake of the above–mentioned omega–6 oils for some reason, consider taking extra omega–3 oils through fish oil supplements.

Quercetin and catechin

A study found out that two phytochemicals, quercetin and catechin, worked together to reduce platelet aggregation. When platelets stick together, it can lead to clot formation and heart attack.

Quercetins are found in leafy vegetables, broccoli, peppers, apples, grapes, green tea, and red wine. Catechins are found in apples, apricots, peaches, cherries, strawberries, and raspberries.

Take foods rich in quercetins and catechins.

They need not be eaten together.

Read here for more such combinations: Food synergy: Nutrients that work better together.


I hope this article has conveyed to you that unlike most medical drugs, nutrients work together.

Nutrients are best understood as a sports team. Various players on the team play different roles. In a football (soccer) team, some players might play a more glamorous position (score goals) but everyone has a role. Remove the goalie, and you will not win the match even with the best goal–scoring players. Nutrients work exactly like that.

Some people bring the medicine–world thinking to nutrients. So they consider nutrients as lone warriors, such as weight–lifters or high jumpers.

A weight–lifter either manages to lift the weight, or does not. A high jumper either clears the bar, or he does not. Their actions, and results, have nothing to do with what their competitors, or colleagues, do. Their performances, therefore, should be judged as purely theirs, in isolation.

But nutrients don’t work that way. Consider the great football player of yesteryears, Pelé. Without meaning any insult, I feel that he would not have done so well if he were playing on the Mongolian football team. Some of his efficacy was also because of his teammates, who perhaps created many goal–scoring opportunities for him.

Similarly, almost all nutrients need assistance from their nutrient colleagues for proper functioning. In essence, nutrients should never be evaluated in isolation.

In contrast, medicines are usually lone warriors. They work without any other supporting medicines. So their efficacy should be judged in isolation. If they work, or don’t work, the entire credit, or discredit, should go to them, and them alone.

As a result, any research, or clinical trial, testing the efficacy of a single nutrient is far more difficult. It will need an approach called pari passu. In Latin, ‘pari passu’ means ‘all other things remaining equal’.

In other words, the trial will have to ensure the status of all other combining nutrients in the bodies of all participants the same, which is practically impossible. So, all the results of such trials, especially negative, should be taken with a grain of scepticism.

Now, put your thinking hat on and figure out why negative results (no benefit found) should involve more scepticism than positive results (nutrient found to be beneficial). Hint: to prove that black swans exist, you have to show one black swan at one place. To prove that black swans don’t exist, you have to show no black swan exists, at all places around the world.

Read on this website, a very comprehensive article on how to correctly interpret results of research involving nutrients.

In conclusion

Many nutrients work together. The efficacy of one is changed by the presence of another.

Don’t look at a single number for any nutrient in isolation.

Take research reports purportedly claiming inefficacy of any single nutrient with a pinch of salt.

Do your homework, before increasing intake of any nutrient.

Follow the tips given above, after each nutrient combination discussed.

First published on: 29th July, 2009


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