Vitamins are substances that are essential for life. The word “vitamins” comes from the Latin ” vita “, meaning ” life “. They are involved in a whole series of chemical reactions that are essential to the normal functioning of our bodies. Unfortunately, we cannot synthesise these precious substances ourselves. We have to provide them through our diet. Generally speaking, a balanced diet should provide us with sufficient quantities of the 13 vitamins.
There are times in our lives when our vitamin requirements are increased: pregnancy, illness, growth, periods of confinement, etc. There are ways of preserving and assimilating these precious vitamins, which are vital and essential to our bodies. And when our diet is no longer sufficient, we need to increase our intake through food supplements.
What is a vitamin?
Vitamins are organic substances that are essential for our bodies to function properly. They play a crucial role in many biological processes. Unlike macronutrients such as carbohydrates, proteins and fats, vitamins are needed in small quantities to maintain good health. They cannot be produced in sufficient quantities by the human body, so it is essential to obtain them from food or supplements. Vitamins are involved in functions such as cell growth, wound healing and immune system support. Their absence or insufficiency in the diet can lead to various deficiencies and illnesses.
The different categories
Vitamins are classified into two main categories based on their solubility: water-soluble vitamins and fat-soluble vitamins.
- Water-soluble: These vitamins dissolve in water. The body does not store them in large quantities, so they need to be taken in regularly through the diet. Excesses of these vitamins are generally eliminated through the urine. This category includes B-group vitamins (B1, B2, B3, B5, B6, B7, B9 and B12) and vitamin C. These vitamins are essential for energy metabolism, the formation of blood cells and the maintenance of skin and nerves.
- Liposoluble: These vitamins dissolve in fats and oils. They can be stored in the liver and adipose tissue of the body, so they can be used when needed. However, excessive consumption can lead to hypervitaminosis. Fat-soluble vitamins include vitamin A, essential for vision and bone growth; vitamin D, crucial for calcium absorption and bone health; vitamin E, a powerful antioxidant; and vitamin K, necessary for blood clotting.
Water-soluble vs. fat-soluble vitamins
The main difference between these two groups lies in the way they are stored and used by the body. Water-soluble vitamins, which require daily or regular consumption, present a higher risk of deficiency, but a lower risk of intoxication. Fat-soluble vitamins, on the other hand, although less frequently required, can accumulate in the body and present a risk of intoxication if consumed in excess. It is therefore crucial to balance vitamin intake, taking into account their solubility and storage capacity, to maintain optimal health.
Where can I find vitamins?
Vitamins are essential for a number of bodily functions and must be provided by our diet or by supplements, as our bodies are unable to produce them in sufficient quantities. Each vitamin has specific sources and it is important to know what these sources are in order to maintain a balanced diet and prevent deficiencies.
Food sources
Food sources of vitamins vary depending on the vitamin in question. Here are a few examples:
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Fat-soluble :
- A: found in liver, dairy products, eggs and green leafy vegetables.
- D: found in oily fish and fish liver oil, and synthesised by exposure to the sun.
- E: abundant in vegetable oils, nuts, seeds and green vegetables.
- K: found in green leafy vegetables, vegetable oils and certain fruits.
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Water-soluble :
A varied and colourful diet is generally a good indicator of adequate vitamin intake, as the different colours of fruit and vegetables represent different nutrients and vitamins.
Multivitamin food supplements: benefits and precautions
Vitamin supplements can be beneficial in certain situations, such as when it is difficult to meet vitamin requirements through diet alone, or when there is a proven deficiency. However, they should be used with discretion:
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Advantages:
- They can help to offset nutritional deficiencies, particularly in individuals with increased needs (pregnant women, the elderly, strict vegetarians).
- They are useful in regions where access to a variety of vitamin-rich foods is limited.
- They can support the immune system, improve cognitive performance and reduce the incidence of certain diseases.
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Precautions:
- Supplements should not replace a balanced and varied diet.
- It is important to follow the recommended doses, as an excess of fat-soluble vitamins can have toxic effects.
- Before starting any additional treatment, it is advisable to consult a health professional to assess your real needs.
Taking supplements must therefore be an informed decision, taking into account the potential benefits and risks associated with overdosing or interactions with other medications.
What is the difference between deficiencies and deficiencies?
A vitamin deficiency, also known as avitaminosis, is characterised by a shortage or absence of vitamins essential for the body to function properly. This deficiency may be the result of an inadequate diet or an absorption problem in the digestive system.
The symptoms associated with a vitamin deficiency do not appear immediately, but set in gradually. They become evident when the body has exhausted its vitamin reserves. Prolonged deficiency can lead to specific pathologies, which generally improve when vitamin intake is restored.
- For example, a vitamin C deficiency leads to scurvy, while a lack of vitamin D can cause rickets. In developed countries, thanks to a varied and enriched diet, diseases linked to vitamin deficiency have become rare. However, this reality differs in contexts of undernutrition, where these diseases remain prevalent.
Although deficiency-related illnesses are uncommon in industrialised countries, vitamin deficiency, or hypovitaminosis, is nonetheless common. This situation can affect general health and occurs when vitamin intake is insufficient to cover the body’s increased needs. Situations such as pregnancy, growth in children, or certain chronic illnesses can increase vitamin requirements and risk leading to a deficit if the diet does not keep up.
Maintaining a balanced, nutrient-rich diet is therefore essential to prevent vitamin deficiencies and ensure optimal health. It is important to be alert to the warning signs of hypovitaminosis so that you can intervene quickly and adjust your nutritional intake if necessary.
Who is at risk of vitamin deficiency?
Insufficient intake can affect people in the following situations:
- People in retirement or nursing homes
- Anorexics
- People on inadequate weight-loss diets
- Edentulous
- People suffering from chronic intestinal disorders
- People on long-term medication
Increased needs can affect people in the following situations:
- Young people in their growth period
- Sports enthusiasts
- Pregnant or breast-feeding women, or those on oral contraceptives
- When taking certain medicines
- Smokers: vitamin C and A requirements are increased because nicotine causes faster vitamin loss through tissue desaturation
- Alcoholics (vitamins A, B1, B12, B6, C)
- People living in polluted environments may have increased vitamin requirements, especially vitamin D (reduced skin synthesis due to sunlight re-education caused by industrial fumes), as well as vitamins A, E and C
What can cause a vitamin deficiency?
| Cause | Description |
|---|---|
| An unbalanced diet | Insufficient intake of essential nutrients is often due to excessive consumption of fast food and ready-made meals. |
| Depression | Depression can reduce appetite and lead to inappropriate eating. |
| Anorexia | Anorexia causes severe food restriction and can lead to serious deficiencies. |
| Digestive disorders | Diseases that affect intestinal function can impair the absorption of nutrients and lead to deficiencies. |
| Acute digestive disorders | Disorders such as constipation or intestinal infections can disrupt the intestinal flora and the absorption of nutrients. |
| Chronic digestive disorders | Chronic diseases of the intestine can reduce the absorption of nutrients, leading to deficiencies. |
| Dental problems | Dental problems can limit the intake of nutritionally rich foods and lead to deficiencies. |
| Surgical intervention | Digestive surgery can affect nutrient absorption and require the use of multivitamin supplements. |
| Taking medication | The use of certain medicines can interfere with the absorption of vitamins and reduce their availability. |
The main causes of vitamin loss
- Sifting (separation of bran and flour) is often excessive. Extensive sifting produces very white flour. But this results in a significant loss of vitamins: 2/3 of group B vitamins are lost. So ‘white’ bread is much lower in vitamin B1 (0.08 mg per 100g) than ‘wholemeal’ bread (0.25 per 100g). That’s why it’s a good idea to opt for products made with organic wholemeal flour for a higher intake of nutrients.
- Skimming milk removes most of the fat-soluble vitamins.
- Blanching vegetables before preserving or freezing is designed to improve their quality and reduce the volume of the food. It involves scalding or steaming the vegetables. Losses due to scalding can be as high as 60% for vitamin C, 30% for B1 and 40% for B2.
- Dehydration
- Cooking: Prefer gentle steaming, which denatures food much less.
- Our l ifestyles mean that we eat more and more ready-made meals and less and less fresh food. While industrial ‘ready-to-eat’ foods make life much easier, they are also partly responsible for a significant loss of vitamins…. As we have just seen, this is due to food processing and preservation technologies.
Impact on health
Vitamin deficiency can have many negative consequences for human health. It occurs when vitamin intake is insufficient to meet the body’s daily needs. This deficiency can result from an unbalanced diet, absorption disorders, certain chronic illnesses, or increased requirements during specific periods such as pregnancy. The effects of such a deficiency depend on the vitamin concerned, and can range from a slight reduction in bodily functions to serious, life-threatening disorders.
Consequences on physical health
Vitamin deficiencies affect many bodily functions and can lead to various pathologies:
- D: It can lead to rickets in children and osteomalacia in adults, characterised by softening and brittleness of the bones.
- A: It is one of the main causes of blindness worldwide, particularly in children. It can also weaken the immune system and increase the risk of infection.
- Group B: It can cause anaemia (B9 and B12), neurological disorders (B12), beriberi (B1), pellagra (B3), skin lesions and increased susceptibility to infections.
- C: It can cause scurvy, a disease characterised by fatigue, inflamed gums, small skin haemorrhages and tooth loss.
Impact on mental health
Deficiencies can also have a significant impact on mental health:
- Group B: Particularly B6, B9 (folic acid) and B12, is associated with an increased risk of depression and cognitive decline. This is because they are crucial for the production of neurotransmitters such as serotonin and dopamine, which play a role in regulating mood and cognitive function.
- D: It has been linked to an increased risk of mood disorders, particularly depression and anxiety. It is also involved in the regulation of numerous brain processes.
