All you need to know about vitamins: requirements, rich foods, benefits

We learned about macronutrients – Protein, Carbohydrates, Lipids - in the previous chapters. We're now going to tackle the micronutrients, which are made up of vitamins and salts. minerals. Let's start with vitamins!

Vitamins: what are they and what are they good for?

Vitamins are organic materials who work in essential biochemical functions. Among other things, they regulate metabolism, facilitate energy release, and perform important functions in bone and tissue synthesis.

For example, vitamins C and D are involved in bone metabolism. Vitamin C preserves the integrity and elasticity of skin, mucous membranes and blood vessels. The vitamin A supports the metabolism of retinal tissues, as well as skin and mucous membranes. Finally, vitamins E and C neutralize free radicals, while vitamins B2 and B3 are involved in energy production.

In contrast to macronutrients, vitamins are micronutrientsIn other words, our bodies need them in small quantities. They must be supplied regularly and in sufficient quantity through the diet, as the body cannot synthesize them, except for vitamin D and vitamin C. vitamin K.

There are no fewer than 13 vitamins, divided into two groups: the fat-soluble vitamins (soluble in fats) and water-soluble vitamins (water-soluble). The former can be stored in fats, making them toxic in high doses, while the latter are eliminated via the urinary tract if they are in excess.

Fat-soluble vitamins

Fat-soluble vitamins are stored in adipose tissueThis can make them toxic in high doses. This property also means that they can be taken less regularly than water-soluble vitamins.

Generally speaking, fat-soluble vitamins are supplied by dietary lipids (oils, fatty fish, egg yolk, offalThe only exception is vitamin D, whose main source is the sun (hence the vitamin D deficiency in winter).

Fat-soluble vitamins include the following :

• Vitamin A
• Vitamin D
• Vitamin E
• Vitamin K

Water-soluble vitamins

Water-soluble vitamins are not stored, are soluble in water, and are easily eliminated through urine (except for vitamin B12). Their maximum effect in the body occurs 8 to 14h after ingestion. They are mainly provided by fruit and vegetables. vegetables.

Water-soluble vitamins include the following :

• Vitamin C
• Group B vitamins : Vitamin B1, B2, B3 or PP, B5, B6, B8, B9 and B12.

Vitamin deficiencies

There are many signs that can indicate a vitamin deficiency. These include fatigue, lack of concentration, depression, digestive problems, easy bruising, etc. Sometimes it's necessary to supplement with vitamins in addition to those found in the diet.

Needs vary according to age, sex, build and state of health. Some people need more vitamins, particularly athletes, teenagers, the elderly and pregnant women. Pollution and lack of sunlight also increase our need for vitamins.

In developed countries, deficiencies in vitamins A, E, K, B1, B2, B3 and B5 are fairly rare. However, they are more frequent for vitamins B9, B12, C and D..

Be careful, however: too many vitamins do not improve the performance of a body that is already functioning normally. Over-consumption can have toxic effects in the medium to long term. Conversely, an insufficient intake can lead to deficiencies, or even deficiencies associated with clinical and/or pathological disorders.

But how do you know which vitamins to take at what times, and for whom? To answer these complex questions, which depend on many factors, let's take a quick look at each vitamin. For each of them, you'll know intuitively whether you need to supplement or cut back, provided you check with a health check-up afterwards.

Let's start with the first, vitamin A.
Previous chapter: Focus on lipids