How familiar are you with the “sunshine vitamin,” vitamin D? Your body naturally produces vitamin D when exposed to direct sunlight.
In fact, sunlight is the main source of vitamin D. The body's ability to synthesize this vitamin depends on the individual, their age, pigmentation, habits and exposure to the sun.
However, sun exposure carries many risks for your health: skin cancer, dehydration, burning, fatigue... This is why it is best to obtain vitamin D through nutrition from foods or supplements.
It's estimated that by the end of winter, between 40% and 50% of French people are vitamin D deficient, and interest in vitamin D and its role in our overall health is growing. Vitamin D affects many bodily functions, such as bone health. Vitamin D deficiency often leads to muscle weakness, fatigue, and depressed mood. Studies also suggest that low vitamin D levels may be a risk factor for autoimmune diseases.
What is the recommended daily dose of vitamin D?
The recommended intake of vitamin D is 15 micrograms per day. It's important to note that vitamin D content is often indicated as a percentage on the nutrition label of food packaging. This tells you how much vitamin D the food will provide per day.
Why is vitamin D important and what are its functions?
Vitamin D has several important functions. The most vital are regulating calcium and phosphorus absorption and facilitating immune system function. Getting enough vitamin D is important for the growth and development of bones and teeth, as well as for better resistance to certain diseases.
Vitamin D is necessary for the absorption of calcium in your body. This plays a key role in maintaining bone strength and skeletal integrity. Getting enough vitamin D and calcium is essential for maintaining bone health and protecting against conditions like osteoporosis.
- Reduce the risk of multiple sclerosis.
- Reduce the risk of heart disease. Low vitamin D levels have been linked to an increased risk of heart diseases such as hypertension, heart failure, and stroke.
- Reduce the risk of serious illness. Although studies are mixed, low vitamin D levels contribute to acute respiratory distress syndrome.
- Support immune health. People who do not have adequate vitamin D levels may be at increased risk of infections and autoimmune diseases.
Research has shown that vitamin D may play an important role in regulating mood and reducing the risk of depression. Other studies have identified low vitamin D levels as a risk factor for more severe symptoms of fibromyalgia, anxiety, and depression.
What are the symptoms of vitamin D deficiency?
Symptoms of vitamin D deficiency in adults may include:
- fatigue, aches and pains
- severe bone or muscle pain or weakness
- stress fractures, particularly in the legs, pelvis, and hips
A vitamin D deficiency is easily diagnosed with a simple blood test. If you have a deficiency, your doctor will likely recommend supplements and, depending on the deficiency, order X-rays to check your bone strength. You should also make sure you're getting vitamin D from sunlight and the foods you eat.
What foods contain vitamin D?
Discover the list of foods rich in vitamin D:
Cod liver oil.
It is the richest food in vitamin D with 54.3 µg per 100 g. It has been used for many years to treat vitamin D deficiency. It has also been used in the treatment of rickets, psoriasis, and tuberculosis.
It is also very rich in vitamin A, with 150% of your daily intake in just one teaspoon (4.9 ml). Vitamin A can be toxic in large amounts. The safe upper limit for vitamin A is 3,000 mcg. Just one teaspoon (4.9 ml) contains 1,350 mcg of vitamin A, so be sure not to exceed the upper limit with cod liver oil or any other vitamin A supplement.
Additionally, this oil is rich in omega-3 fatty acids. Omega-3s can play a role in heart health and reduce inflammation in the body. Along with fatty fish, cod liver oil is another source of these fatty acids. If you don't eat fish, it can be difficult to get enough omega-3s in your diet.
Salmon.
It is an oily fish and an excellent source of vitamin D.
A 100 gram serving contains between 6 and 23 µg of vitamin D.
Whether it's wild or farmed can make a big difference in vitamin D content. On average, wild salmon contains more vitamin D. The amount of vitamin D varies depending on where the salmon is caught and the time of year. If you don't like that, you can opt for trout.
The herring.
Herring and mackerel are consumed worldwide and are among the foods rich in vitamin D. They are often smoked or pickled. Herring, in particular, is an excellent source of vitamin D, with 22µg per 100g.
Sardines.
For sardines, you should count 12.3µg per 100g of grilled sardines and 10.8 µg/100g of sardines in oil.
Canned tuna.
Many people enjoy canned fish because of its flavor and easy storage methods. It's usually cheaper than buying fresh fish.
Raw tuna is also a good source of vitamin D with 7.2 µg/100 g, and 6.1 µg/100 g for its canned natural version.
Be careful, however, as it often contains mercury, a heavy metal. The amount of mercury depends on the type of fish. Over time, methylmercury can build up in your body. In some cases, this can lead to serious health problems.
Egg yolk.
Whole eggs are another good source, as well as a wonderfully nutritious food. Most of the protein in an egg is found in the white, and the fat, vitamins, and minerals are mainly found in the yolk.
The yolk of a large egg contains 3.2µg of vitamin D.
Choosing eggs from chickens raised outdoors or marketed as vitamin D-rich or other foods can be a great way to meet your daily needs.
Mushrooms.
Besides fortified products, mushrooms are the only sufficient non-animal source of vitamin D.
Like humans, they can synthesize vitamin D when exposed to UV light. However, they produce vitamin D2, while animals produce vitamin D3. While vitamin D2 helps increase blood levels of vitamin D, it may not be as effective as vitamin D3.
Some wild mushrooms, such as morels, are excellent sources of vitamin D2 due to their exposure to UV rays. Commercially available mushrooms are often grown in the dark and contain very little D2. However, they may have been treated with ultraviolet (UV) light to increase their vitamin D content.
Chanterelles contain 5.3 µp per 100 grams, followed by morels with 5.1 µp/100 g. Shiitake mushrooms contain 3.9 µp/100 grams.
Dark chocolate.
When it contains at least 40% cocoa, chocolate is one of the foods rich in vitamin D. Dark chocolate contains on average 5 µg of vitamin D per 100g.
