5 minImagine: it's a sunny day, you're enjoying the warmth on your skin, and meanwhile your body is hard at work producing one of the most essential vitamins for your health — vitamin D! But what if the sun doesn't shine very often, or if you spend a lot of time indoors? In this article, we'll talk about why vitamin D is so important, what it does for you, and how to make sure you get enough of it, even without sitting in the sun every day.
In this article, you will learn
- What vitamin D actually is and why you need it
- The different types of vitamin D
- How much vitamin D you need every day
- What happens if you have a deficiency or, conversely, if you get too much vitamin D
- Whether you should take a supplement, and for whom it is useful
What is vitamin D?
Vitamin D is a fat-soluble vitamin that is best known as the “sunshine vitamin”. Your body produces it when your skin is exposed to sunlight. It plays an important role in your health because it helps absorb calcium and phosphorus, which are essential for strong bones and teeth. It also supports your immune system and ensures that your muscles continue to function properly.
Forms of vitamin D
There are five forms of vitamin D, called D1 to D5. For humans, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) are particularly relevant. The other forms, such as D1 and D4, are rarely used, while D5 is a synthetic variant that is mainly used in research.
The main difference between vitamin D2 (ergocalciferol) and D3 (cholecalciferol) lies in their origin and effectiveness.
- Vitamin D2 (ergocalciferol): is plant-based and occurs in mushrooms such as shiitake and button mushrooms, which, like humans, produce vitamin D through sunlight (UV light). Vitamin D2 is mainly used in vegetarian supplements, but it is less easily absorbed and converted by the body than vitamin D3.
- Vitamin D3 (cholecalciferol:) is a form that the body produces itself through the skin and is also found in animal products such as fatty fish, meat, eggs and baking and frying products. However, vitamin D3 is also found in some plant-based products: algae and lichen are an ideal solution for vegans.
Want to know more about the differences between vitamin D2 and D3?
The most absorbable form of vitamin D
The form of vitamin D that is best absorbed by the body is vitamin D3 or cholecalciferol. This is the most natural form of vitamin D and is the same as the vitamin D produced by our bodies under the influence of sunlight.
What is vitamin D good for?
Vitamin D is necessary for the absorption of calcium and phosphorus in the body, which keeps bones and teeth strong. It also plays an important role in the immune system and cell growth.
Vitamin D3 (cholecalciferol) is also an important vitamin for proper muscle function and calcium absorption from food.
Here is a list of all the processes to which vitamin D contributes:
- Helps maintain a healthy immune system
- Plays a role in maintaining supple and strong muscles
- Plays a role in tissue growth and cell division
- Increases calcium absorption in the bones
- Supports the body's immune system
- Helps ensure the normal functioning of the immune system
- Good for the skeleton
Vitamin D in food
Foods rich in vitamin D3 are mainly of animal origin. The largest source of vitamin D is oily fish. Examples of oily fish are mackerel, herring and salmon. Vitamin D is also found in meat, eggs and as an additive in low-fat margarine, margarine and cooking and frying butter, but to a lesser extent than in fish.
Vitamin D3 can be produced from animal vitamin D3 from lanolin (wool grease). It can also be produced from cod liver oil. Cod liver oil comes from the liver of cod, haddock or halibut, among others.
For people who prefer not to take animal-based vitamin D3, including vegetarians and vegans, there is a plant-based source of vitamin D3. These are algae or lichen.
Vitamin D surplus
An excess of vitamin D occurs when you consume more than 100 micrograms of vitamin D per day for a prolonged period of time. Vitamin D is a fat-soluble vitamin that is not simply excreted in your urine when you have an excess. The acceptable upper limit is set at 100 mcg per day; as long as you stay below that, you will never consume too much.
Vitamin D deficiency
You can recognise a vitamin D deficiency by various symptoms, namely:
- Fatigue or lack of energy
- Weaker bones
- Bleeding gums
- Pain, tremors or cramps in muscles and joints
- Lethargy
- Anxiety attacks
A prolonged vitamin D deficiency can lead to softening of the bones (osteomalacia). In adults and the elderly, osteomalacia can eventually lead to osteoporosis. Osteoporosis is bone decalcification that occurs in later life. Older people can develop weaker bones and break them more easily.
A vitamin D deficiency can cause rickets (English disease) in young children. This disease causes skeletal abnormalities.
Unfortunately, vitamin D deficiency is common in many people, and not only in winter.
Recommended amount
The recommended daily amount is 10 micrograms of vitamin D. For people over 70, the recommended daily amount is 20 micrograms.
Need a vitamin D supplement?
Because some groups of people need more vitamin D than they can get from food and because some people do not spend enough time in the sun to produce sufficient vitamin D, a number of recommendations for supplementation have been drawn up:
Recommended daily intake for adults (supplementation):
- Women aged 18-49 with a dark skin tone: 10 mcg
- Women aged 18-49 who do not spend much time in the sun during the day or who wear covered clothing: 10 mcg
- Women aged 50-69: 10 mcg
- Women aged 70 or older: 20 mcg
- Pregnant women: 10 mcg
- Men aged 18-69 with a dark skin tone: 10 mcg
- Men aged 18-69 who do not spend much time in the sun during the day or who wear protective clothing: 10 mcg
- Men aged 70 or older: 20 mcg
Recommended daily intake for babies, toddlers and children (supplementation):
- From 0-3 years: 10 mcg
- From 4-17 years (if they do not spend much time in the sun during the day or wear covered clothing): 10 mcg
- From 4-17 years with a darker skin tone: 10 mcg
Acceptable upper limit
Recent research by the EFSA has established a revised upper limit for vitamin D. For adults, this upper limit is 100 mcg. For children aged 1-10 years, the upper limit is 50 mcg, and for children aged 11-17 years, the upper limit is also 100 mcg.
Vitamin D and pregnancy
Are you pregnant? The Health Council of the Netherlands recommends that pregnant women take an extra 10 micrograms (400 IU) of cholecalciferol (vitamin D3) daily as a supplement to their diet. Preferably, do not take more than 100 micrograms (4,000 IU) of vitamin D per day.
During breastfeeding, the recommended amount for healthy mothers is 400 IU (10 micrograms) per day.
