High-dose vitamins help the immune system! Is that really true?

The following contains my personal opinion, experience and principles that I myself follow. I am not aiming for a scientific explanation, but to make this understandable for those without background in physiology or biochemistry.

The body is a complex system

Your body is made up of many billions of cells. These cells group into tissues and accordingly perform unique tasks. Bone-building and bone-resorbing cells are responsible for forming and remodeling your bones according to load. Muscle cells group in muscles and provide movement, blood cells make up the blood and transport nutrients and oxygen back and forth. Nerve cells are found in the brain, spinal cord and nerves and play a role in controlling function. There are many types of cells and tissues, each doing something different.

Tissues do not work separately but in close connection with each other, cooperating, helping or sometimes counterbalancing one another.

This is a little like the structure of society. There are politicians, businesspeople, lawyers, civil servants, teachers, police officers, workers… many functions that serve a particular task, but overall are necessary for society to work. Because people’s lives are finite, when members drop out, others replace them. Your body works in much the same way.

Your cells have a limited lifespan (usually a few days or weeks) and are constantly dying. However, your body contains a self-repairing, restorative system that breaks down the dead cell and replaces it with a new one. It maintains function throughout your life. It fixes errors, injuries and changes caused by disease.

What does this miracle require?

Your cells need energy, oxygen, water, nutrients and minerals, vitamins and trace elements to function (each in a certain amount).

Every single cell contains mitochondria. There may be a few or several thousand of them in a cell. The mitochondrion is the cell’s energy-producing center, so it makes sense that there are more where metabolism is more intense. Energy is produced mainly by burning fuel derived from the breakdown of carbohydrates, fats and, to a lesser extent, proteins.

You bring the raw materials into the body through food and during digestion you break them down into molecules that your body then uses in energy-producing and building processes.

Renewal and protein production also take place in the cells, specifically involving ribosomes and the Golgi apparatus. With the help of the DNA in the nucleus and its copy (mRNA), exactly the protein required for repair is produced in the cell.

But you can only build if all necessary raw materials are available! If something is missing, the process stalls. For example, if there is not enough energy, amino acids, vitamins or minerals, then there is "nothing to" create the new material from.

Your body’s function is determined by the quantity of the scarcest substance.

What does this mean?

I will try to explain with an example.

Imagine building a house. You buy a lot of bricks, you have electricity, water, a cement mixer, the mason comes with his tools and helpers. But you forgot the mortar… How many bricks will they stack on top of each other? None, because there is no mortar. Bringing twice as many bricks won't help because the mortar is missing.

It would also cause a problem if you had enough bricks and mortar but the mason didn’t bring his tools. He could still build, but progress would be much slower and the quality wouldn't meet expectations.

Returning to your body: if your diet does not provide enough of every necessary raw material, it will not (cannot) function properly. If the rebuilding and self-repair processes do not work, your body’s functioning will "stutter" and eventually reach a diseased state.

Balance is key

Proper functioning primarily requires a balanced diet so that there is enough of each substance for your body’s continuous and efficient operation.

Low intake

If you consume too little, you will lack what is needed for proper function. As a result, destroyed tissues are not replaced, organ function deteriorates, your immune system’s defensive ability declines, inflammations and wounds do not heal, and broken bones fuse slowly. Numerous functional disorders can occur depending on which substance or substances are deficient.

Excessive intake

If you take too much of something, it becomes surplus and must be stored.

Take energy needs as an example. You can most easily provide them with carbohydrates. Your body breaks these down into glucose, and cells burn it in the mitochondria to create energy in the form of ATP. If you consume too many carbohydrates, you will not have more energy because your body stores the excess as fat, i.e., you become overweight. Obesity is a source of many diseases.

But let's look at another example. The potassium ion has a very important role in cell function. It is fundamentally necessary for the proper functioning of muscles, the heart and nerves, and for nerve cells to conduct electrical impulses. Knowing this, you might think, let’s eat a few spoonfuls of it. In such doses, however, it is harmful!!!! Hyperkalaemia (that is, an excessive amount of potassium in the blood) can cause serious disturbances. In mild cases a cardiologist may notice small deviations on the ECG, but it can cause arrhythmia and, in severe cases, can stop your heart (i.e., excessive potassium intake can kill you).

My opinion

Based on the above, I am not in favor of any extremes.

Taking a single substance (for example B, D or C vitamin) in high doses is reasonable only to quickly correct deficiency symptoms, and even then only for a few days.

I consider it downright foolish to take only vitamin D for weeks on end (for example assuming it protects against COVID). That is like buying three times as many bricks for building a house and expecting it to be finished faster. More bricks will not get you moved in sooner. Many things are needed for completion and a little of each. Just enough so that, piece by piece, the whole comes together. While you may need thousands of bricks or tiles, you only need one or two faucets or toilet bowls.

In addition to the fundamentally important macronutrients (carbohydrates, fats, proteins), your body needs dozens of vitamins, minerals and trace elements for proper functioning and for healthy regenerative, self-healing processes. So you need a bit of everything. Your body will not work effectively because you "overdo" certain substances, but because you provide it with everything it needs.

A varied diet rich in vegetables and fruits can provide this by itself, especially in rural environments where you can grow your own organic produce.

If you are worried that you might be lacking something and want to supplement, don't pick just one out of the many! Alongside a varied diet, a supplement that contains all the vitamins, minerals and trace elements from A to Z in small doses can make sense. That way you will have enough of everything and your body can function properly.