Vitamin D3: benefits, dosage, side effects

SUMMARY :

What is Vitamin D3?
What is vitamin D3 used for?
How to take vitamin D3? In what form ?
Where to find vitamin D3?
What foods are rich in vitamin D3?
How much vitamin D3 to consume each day?
Vitamin D3 deficiency: symptoms and people at risk
Vitamin D3: what precautions?

What is Vitamin D3?

Vitamin D3 is one of natural forms of the vitamin D. She is also called cholecalciferol. Like vitamin D2, vitamin D3 is an organic secosteroid molecule.

Produced by animals (and therefore also by us, as mammals), vitamin D3 is synthesized by the skin under the action of ultraviolet B rays issued by the sun. Transformed by the kidneys and the liver, it is then stored in the fatty tissues of the body, such as the liver, the muscles and the fats. Cholecalciferol can also be obtained through food, from animal sources such as fatty fish or cod liver.

What is the difference with vitamin D2?

Vitamin D2, also called ergocalciferol, is mainly of plant origin. It is synthesized in fungi when they are exposed to artificial ultraviolet light. Vitamin D2 is also used in vitamin supplements, including products for people on a vegan diet.

Once ingested, both vitamin D3 and vitamin D2 undergo chemical transformations in the liver and kidneys to become an active form of vitamin D used by our body. The main difference between these two forms of vitamin D is in their effectiveness and retention in the body. Studies have shown that vitamin D3 is more effective in raising and maintaining vitamin D levels in the blood, and that it is better absorbed and used by our body compared to vitamin D2. Therefore, vitamin D3 is generally considered the preferred form of vitamin D supplementation.

What is vitamin D3 used for?

Vitamin D3 has many benefits. She plays a major role in the calcium and phosphorus metabolism in the organism. It also guarantees the maintenance of calcium and phosphorus levels in the blood. Thanks to vitamin D3, calcium binds better to bones, cartilage and teeth. This vitamin also has an impact on nerve transmission and muscle contraction.

This vitamin is especially important for infants and the elderly. In the former, it helps prevent rickets, that is to say a lack of calcification of the bones and cartilage, causing problems with bone growth. In the latter, vitamin D3 is essential to avoid osteomalacia (bone decalcification), osteoporosis and muscle weakness, which can lead to falls.

Among the diseases linked to the lack of vitamin D3 are also hyperparathyroidism (excessive production of parathyroid hormone), cirrhosis and liver failure. According to a 2018 study published in the European Journal of Clinical Nutrition, vitamin D can relieve symptoms related to irritable bowel syndrome. In addition, vitamin D3 has benefits for the morale of the elderly. A lack of vitamin D can lead to depression, as shown in a Dutch study published in 2008 (Archives of General Psychiatry).

How to take vitamin D3? In what form ?

Vitamin D3 is industrially produced from lanolin (sheep’s wool fat) and marketed as dietary supplements. These exist in different forms: injectable solution, ampoules, chewable tablets, capsules, drops, but also sprays. Fruit flavored sublingual spray is often recommended for young children. Vegetable vitamin D3, intended for vegans, is produced from lichens. There is also organic vitamin D3. Here are some examples of products and their shapes:

Pediakid Vitamin D3 and D.Plant Vitamin D3: dropper bottles;
Calcidose Vitamin D3 and Cacit Vitamin D3: sachets of powder with calcium and vitamin D3 for oral solution;
Orocal Vitamin D3: lozenges;
Solgar Vitamin D3: gel capsules;
Caltrate Vitamin D3: tablets to swallow.

Where to find vitamin D3?

Under the effects of UVB rays from the sun, 7-Dehydrocholesterol, a sterol naturally present in the body, is transformed into vitamin D3 in the epidermis. To benefit from the benefits of natural vitamin D3, it is so just expose your skin to the sun a bit. More. the skin is dark, the longer the minimum exposure time should be. Thus, the fair-skinned people need about 15-20 minutes of sun exposure a day, compared to several hours for people with dark skin. However, be careful not to abuse the sun’s rays. In northern countries that lack sunlight in winter, some people turn to supplements to avoid the effects of vitamin D3 deficiency.

Vitamin D3 is also found in some foods, although in limited amounts.

Finally, vitamin D3 ampoules are available in pharmacies, on prescription. In parapharmacies, in organic product stores and on online stores, it is possible to buy food supplements, without a prescription, but with a lower dosage of vitamin D3.

What foods are rich in vitamin D3?

To supplement your vitamin D3 intake, you can eat certain foods that naturally contain it. To know :

fatty fish, such as salmon, herring, mackerel, eel, trout and tuna;
cod liver;
certain dairy products such as milk, yoghurts and cheese;
the egg yolk ;
offal (liver, in particular);
certain mushrooms such as morels, chanterelles and porcini mushrooms.

Cod liver oil is reputed to be one of the richest foods in vitamin D3, with no less than 250 µg/100 g. It is sold in a bottle or in gelled capsules.

How much vitamin D3 to consume each day?

The dosage of vitamin D3 varies by country. In France, the nutritional reference for the population (RNP) in vitamin D, that is to say the dosage of vitamin D recommended for an adult, is 15 micrograms per day. For children under 6 months to 1 year, it is 10 µg/d.

As far as food supplements are concerned, the dosage depends on the product and the vitamin D3 dosage. For example, for a sachet of powder containing 22 µg of vitamin D3, the dosage is 1 sachet per day.

Vitamin D3 deficiency: symptoms and people at risk

A vitamin D3 deficiency and, more broadly, in group D vitamins, can lead to various symptoms. Here are some common signs to look out for:

fatigue and general weakness;
weakened immune system: increased susceptibility to infections, frequent colds and slower recovery from illness;
depression, anxiety and mood disorders;
bone problems: bone pain, increased risk of fractures;
muscle weakness, more frequent cramps;
growth retardation in children;
dental problems.

People most at risk of deficiency

People with limited sun exposure : vitamin D is mainly synthesized by the skin when it is exposed to the ultraviolet rays of the sun. People who spend little time outdoors or have sedentary lifestyles may have an increased risk of deficiency.
Dark-skinned people : the melanin present in the skin acts as a natural barrier to UV rays and can reduce the production of vitamin D. People with darker skin therefore generally need more exposure to the sun to produce adequate levels of vitamin D .
Old people : With age, the ability of the skin to produce vitamin D decreases. Additionally, older people are often less active outdoors and may have less varied diets, which may increase their risk of deficiency.
Exclusively breastfed infants : Breast milk does not contain enough vitamin D to meet the needs of infants. Exclusively breastfed infants therefore have a higher risk of vitamin D deficiency, unless they receive a supplement recommended by their healthcare professional.
People who are obese or have had bariatric surgery : Obesity and weight loss surgery can alter the absorption and metabolism of vitamin D in the body, which can increase the risk of deficiency.
People with certain digestive diseases : Diseases such as celiac disease, inflammatory bowel disease (IBD), and other conditions that affect nutrient absorption may increase the risk of vitamin D deficiency.

Vitamin D3: what precautions?

ANSES (National Agency for Food, Environmental and Occupational Health Safety) sets an upper safety limit (LSS) for daily doses of vitamin D.

For children under 6 months to under 1 year, it is 25 µg/d.
For children from 1 to 10 years old, it is 50 µg/d.
For adolescents aged 11 to 17, men and women aged 18 and over and pregnant or breastfeeding women, the limit is 100 µg/d.

In case of vitamin D3 overdoseside effects include nausea, vomiting, headache, intense fatigue or weight loss.

For some people, vitamin D3 supplements are not recommended. This is the case for patients who have too high a level of calcium in the blood, but also for people with a history of kidney stones containing calcium.

Read also: