In April 2023, the National Academy of Medicine drew attention to vitamin D deficiencies which are affecting more and more people in the West. Indeed, a deficiency of this vitamin leads to many complications, from symptoms of irritability to the development of autoimmune diseases. Nutrimuscle explains how to prevent deficiencies and ensure an adequate intake using foods rich in vitamin D.
- What is Vitamin D?
- Roles and benefits for health and sport
- Risks and deficiencies
- Where can I find vitamin D in food?
- Other Sources
- Treatments and additional contributions
What is Vitamin D?
Vitamin D is a fat-soluble vitamin, that is, it dissolves in fat. Essential to many functions of our body, it exists in two main forms, the D2 form and the D3 form. It is preferable to consume it in its D3 form, because it would be better assimilated by the body. D2 is more sensitive to heat and humidity, so it is considered unstable.
Its roles in the body
Vitamin D plays an important role in many biological processes, both in health and in sport. It is metabolized by the liver to calcifediol and then releases calcitriol, its active form. Its benefits are:
Rickets is a bone disease to which infants are particularly vulnerable. To protect against this, it is important to supplement them with vitamin D. This vitamin plays an active role in bone health. It ensures the strength of the teeth and reduces the risk of fracture. In addition, it helps to fight against osteoporosis, a bone disease that develops in populations of a more advanced age.
Increases athletic performance
In athletes, high cortisol levels prevent muscles from growing and recovering. Indeed, cortisol causes a drop in testosterone levels and has a catabolic action. Vitamin D increases testosterone production and decreases levels of myostatin, a catabolic hormone. In fact, this vitamin increases sports performance by acting on cortisol.
This is reputed to be the vitamin of longevity, according to several studies. It has shown its effectiveness on a group of people with different levels of intake. It has been found that people with a high rate experience an 8% reduction in mortality.
Against fat gain
Vitamin D has been shown to increase metabolism and fat oxidation. Extra intake of this vitamin could contribute to greater fat loss than with a placebo.
Risks and deficiencies
As previously mentioned, vitamin D deficiency in children and adolescents leads to rickets. In adults, it causes osteomalacia or osteopenia.
Some populations are more affected by deficiencies due to lack of sunlight. The National Academy of Medicine has also warned that UV cabins do not replace exposure to the sun. These are factors in the development of cancer.
It is during the cold seasons that there are the most vitamin D deficiencies. This leads to intense fatigue, low motivation, irritability and a weakening of the immune system. In more serious cases, too much of a deficiency can lead to cardiovascular disease and increases the risk of stroke.
Ideally, vitamin D should only be considered as a dietary supplement. Although 10 to 15 minutes of sun exposure a day is sufficient, it can quickly become harmful to the skin.
Sources of vitamin D in food
There are many sources of vitamin D3. It is found in particular in:
- Cod liver oil: 250 µg per 100g, this is the most concentrated source
- Oily fish (tuna, salmon, swordfish, herring, sea bream): between 5 and 10 µg per 100g
- Small fish (mackerel, sardines): about 12 µg per 100 g
- Eggs: 11 µg per 100g
- Dairy products: about 2 µg per 100g
Most people think that the D3 form is only of animal origin. However, boreal lichen has been shown to be an excellent source of vitamin D3. People following a vegan or vegetarian diet are encouraged to consume boreal lichen to benefit from its effects.
Other sources of vitamin D3
Vitamin D can be synthesized from sunlight. According to the National Academy of Medicine, 10 minutes of sun exposure per day is enough to synthesize a daily rate. However, this is not without risk to the skin and is only feasible depending on weather conditions.
The most optimal source is in the form of a dietary supplement. Carefully dosed to meet daily standards, food supplements cover vitamin needs without risking the consumer's health.
At Nutrimuscle, we have made a pharmaceutical grade vitamin D. From the European manufacturer DSM, vitamin quali-D guarantees an optimal dosage for pure quality, without contaminants.
Dosage and cures
According to ANSES in 2022, the recommended daily intakes of vitamin D are:
- 5.2 µg/d for infants (1 to 3 years old)
- 2.6 µg/d for children (4 to 10 years old)
- 2.9 µg/d for adolescents (11 to 17 years old)
- 3.1 µg/d in adults (18 to 79 years old)
It is preferable to supplement throughout the year rather than to carry out short cures. Vitamins act on the long term, the effects are observable after a few months of intake.
What you must remember
To prevent a deficiency and ensure an adequate intake of vitamin D, vary your diet and take supplements.
Refer to ANSES recommendations and take blood samples regularly. Be alert to the symptoms of winter depressions and start taking vitamins before the arrival of the cold seasons. To learn more about vitamin D, read our dedicated article.