What is vitamin D?
Vitamin D is a non-caloric organic substance, essential for our metabolism and good health. Soluble in fats (it is called “liposoluble”, like vitamins A , E and K ), it can be stored in adipose tissues.
Vitamin D acts as a hypercalcemic hormone, thus facilitating the absorption of calcium and phosphorus by the intestines.
Where to find vitamin D?
Vitamin D comes from two sources:
- Vitamin D2 or ergocalciferol: it is of plant origin. It is found in most foods.
- Vitamin D3 or cholecalciferol: it is synthesized in the skin by the action of ultraviolet rays on cholesterol. Vitamin D3 is also present in foods of animal origin such as fish oils.
Both vitamin D2 and vitamin D3 are converted into vitamin D in the body.
We therefore meet our daily vitamin D needs in two ways:
Exposure to the sun
By exposing your skin to the sun for 15 to 20 minutes late in the morning or in the afternoon, you ensure that your body has a sufficient daily intake of vitamin D. But be careful not to overdo it, prolonged exposure is dangerous for your health.
Consumption of foods rich in vitamin D
Here is a non-exhaustive list of foods rich in vitamin D :
- oily fish, such as herring, sardines, salmon and mackerel;
- certain mushrooms, such as chanterelles, porcini mushrooms and morels;
- Dairy products enriched with vitamin D;
- The egg yolk;
- Dark chocolate (plain);
- Breakfast cereals enriched with vitamin D;
- Butter and margarine;
- Offal (especially liver);
- meat (to a lesser extent).
If you do not consume foods of animal origin, you can add vitamin D food supplements. Also, our vegan meal bars and drinks are enriched with vitamins and minerals, including vitamin D.
To ensure a sufficient supply of vitamin D to your body and avoid the occurrence of a deficiency, it is advisable to have a varied and balanced diet all year round, and to consume two portions of fish per week, including one of fatty fish.
You can seek advice from a nutrition professional who can suggest diets adapted to your body.
What is the role of vitamin D?
Vitamin D is essential for the proper functioning of our body. Its main function is to increase blood concentrations of calcium and phosphorus.
Maintaining a good level of calcium in the blood ensures:
- Optimal mineralization of bone, cartilage and tooth tissues;
- Effective muscle contraction;
- Good nerve transmission;
- Adequate coagulation.
Vitamin D is also involved in:
- Hormonal regulation;
- the differentiation and activity of cells of the immune system;
- The differentiation of certain skin cells.
Vitamin D also helps maintain a good immune system, which helps ward off viruses and bacteria, sources of disease.
Many studies have been carried out to find out whether a lack of vitamin D could increase the risk of developing cancer or, on the contrary, whether a higher level of vitamin D could reduce the risk of developing cancer. However, no study has yet proven the link between the quantity of vitamin D and the development of cancer or not.
How much vitamin D do we need?
The amount of vitamin D you need to avoid deficiency depends on many factors including:
- Age
- Ethnicity
- Latitude
- The season
- Exposure to the sun
The National Institutes of Health (NIH) recommends an average daily intake of 400 to 800 IU, or 10 to 20 micrograms. A daily vitamin D intake of 1,000 to 4,000 IU, or 25 to 100 micrograms, should be enough to ensure optimal blood levels in most people.
People who are overweight or obese, pregnant or postmenopausal women may need larger amounts of vitamin D. The limit amount for vitamin D is 4,000 IU/day. Be sure not to take more without consulting a healthcare professional.
What are the symptoms of vitamin D deficiency?
A significant lack of vitamin D in children can cause rickets. Symptoms of rickets include:
- Improper growth due to curved bones.
- Muscular weakness.
- Bone pain.
- Joint deformities.
Children with a mild vitamin deficiency may simply have weak, sore, and/or painful muscles.
Lack of vitamin D is not as obvious in adults. Signs and symptoms may include:
- Fatigue.
- Bone pain.
- Muscle weakness, muscle pain or muscle cramps.
- Mood changes, such as depression.
However, you may not show any signs or symptoms of vitamin D deficiency.
What are the risks of a lack of vitamin D?
The consequences of a vitamin D deficiency on your health are:
- Muscular disorders such as muscle failure, tetany, convulsions;
- Bone disorders such as osteomalacia or osteoporosis in adults, rickets in young people and growing children, which can lead to bone and muscle pain and bone deformities.
- A lack of vitamin D can also lead to reduced bone mass and therefore an increased risk of fractures. These risks are particularly high when the level of physical activity is low.
What are the causes of Vitamin D deficiency?
Deficiency cases are caused by various reasons, here are some of them:
- Not getting the recommended levels of vitamin D. This is likely the case if you follow a strict vegan diet , as most natural sources are animal-based. Our meal bars are enriched with vitamins and minerals.
- Limited exposure to the sun. Since the body makes vitamin D when your skin is exposed to the sun, you may be at risk of deficiency if you have no sun exposure. During winter, vitamin D insufficiency may be more prevalent because there is less sunlight.
- Have dark skin. The pigment melanin reduces the skin's ability to make vitamin D in response to sun exposure. Some studies show that older people with darker skin are at high risk of vitamin D deficiency.
- The kidneys cannot convert vitamin D into its active form. As we age, the kidneys are less efficient at converting vitamin D into its active form, increasing their risk of vitamin D deficiency.
- The digestive tract cannot adequately absorb vitamin D. Certain medical conditions, including Crohn's disease, cystic fibrosis , and celiac disease, can affect your gut's ability to absorb vitamin D from the foods you eat.
- Obesity. Vitamin D is extracted from the blood by fat cells, altering its release into the circulation. People with a body mass index of 30 or more often have low blood levels of vitamin D.
- To be pregnant. Pregnant women need a higher intake of vitamin D. It is therefore essential to increase your vitamin D intake during pregnancy.
In summary
Vitamin D is essential for your health. Light exposure to the sun and a diet consisting of foods rich in vitamin D help prevent vitamin D deficiency. A lack of vitamin D can be dangerous for your health, vitamin D insufficiency manifests itself by several symptoms and can cause diseases like osteoporosis. If you think you may be deficient in vitamin D, please consult a healthcare professional who can prescribe treatment and medications tailored to your needs or seek advice from a nutrition professional who will advise you on a suitable diet to avoid a deficiency. in vitamin D.
