We often think thatexposure to the sun during the summer months is enough to meet our vitamin D needs, but in reality, it is quite insufficient. In addition, vitamin D deficiency can lead to many pathologies. Let's see together what arethe roles of this vitamin and how to avoid deficiencies.

Vitamin D, an essential vitamin

Vitamin D Plays a very important role in many metabolic processes such as intestinal absorption of calcium and of phosphorus, absorption and fixation of the latter two at the bone level, prevention of rickets in children, prevention of osteoporosis in women after menopause and osteomalacia in the elderly, prevention of winter infections by strengthening the immune system, and prevention of certain diseases such as type 1 diabetes, multiple sclerosis, and cardiovascular disease.

Its most important role remains its action at thebone level as it participates in mineralization, bone formation, solidification and renewal.

This vitamin is made by our bodies through regular exposure in the sun in summer before 11am and after 4pm but unfortunately, in our regions, the sun exposure is too low during the winter months, not enough to meet our needs. It is therefore important to complement via diet or even via taking supplements.

Vitamin D in the diet

It is possible to providevitamin D to our bodies via our diet. For this, it is recommended to consume 100 to 120 grams of fatty fish three times a week, which in practice is quite complicated. Moreover, these fatty fish should ideally be sea and wild, such as sardines, mackerel, tuna, cod. It is also possible to consume their oil such as cod liver oil, very rich in vitamin D.

There are other dietary sources of vitamin D, such as shellfish, egg yolks, organ meats (calf's liver, kidneys, ...), whole milk and butter.

Why supplement with vitamin D 

In our countries, 80% of the population is deficient in vitamin D. This is due to our lack of sunny winters and our unbalanced diet, which is why supplementation is often necessary. In addition, supplements are very quickly assimilated by the body, which can be useful in case of deficiency. They exist in liquid form, in capsules or in capsules. But how do you choose these supplements?

The first thing to consider is to favorvitamin D from natural sources, because unlike synthetic sources, this one does not present a risk of overdosing and overdosing can saturate the body, blocking the natural synthesis of the vitamin by the skin.

It is also important to know that there are two forms of natural vitamin D: vitamin D2 or ergocalciferol, which is plant-based, and vitamin D3 or cholecalciferol, which is animal-based.

Vitamin D2

This vitamin is biochemically close to vitamin D3 but the latter is more difficult to assimilate and tends to decrease the vitamin D3 level in the blood. It is found in fungi and yeast. Less effective than its animal equivalent, it is less used.

Vitamin D3

Vitamin D3 is the most commonly used form in dietary supplements because it is very close to vitamin D naturally made by the skin upon exposure to the sun, making it more effective. It usually comes from fish oils, lichen (very interesting for vegetarians or vegans) or lanolin (sheep's wool fat or wax). The latter two are often combined withcoconut orrapeseed oil to facilitate absorption.

Lanolin is the most digestible source and closest to our body's own, which is useful in case of fragile gut or for more sensitive bodies such as children or the elderly.

Recommended Dietary Allowances for Vitamin D

In children from 0 to 1 year old, 400 IU (International Unit) per day is recommended, in people between 1 and 70 years old, 600 IU is recommended and in people over 70 years old, 800 IU is recommended.

In some particular cases such as Pregnancy and breastfeeding, requirements are increased. Therefore, it is recommended to consume 800IU of vitamin D per day.

Small tips

When buying vitamin D in the form of dietary supplements, be sure to check the source of it and opt fornatural vitamin D, and preferably, vitamin D3, which is more effective and more easily absorbed by the body.  

These supplements should be kept away from light and preferably consumed during meals for optimal effectiveness.

However, if you are under medical treatment, consult your doctor to avoid interactions and the risk of overdose.