Conscious nutrition is becoming more and more important. It is important that we provide our bodies with enough nutrients such as proteins, carbohydrates and fats. A very important group are the vitamins. Our body cannot produce vitamins itself, so we have to take them in extra.
Vitamin D is extremely relevant for our bones. Vitamin D is also very important for our immune system. If you have a vitamin D deficiency, there may be consequences that you should not underestimate.
This article is intended to give you an understanding of the most important functions of vitamin D, as well as the causes and consequences of a deficiency. We also answer the question about the best time of day to take vitamin D.
the essentials in brief
- Vitamin D is important for calcium balance and bone mineralization.
- We can absorb vitamin D naturally through exposure to the sun as well as through food.
- You should definitely consult your doctor before you start taking vitamin D.
Definition: What is vitamin D?
Vitamin D is a group of fat-soluble vitamins. They are important for the calcium balance and the mineralization of the bones. Vitamin D can be obtained from food or made by the body from exposure to sunlight. It is converted in the body to the hormone calcitriol.
How does vitamin D work?
Vitamin D plays the most important role in the bones. Here, calcitriol promotes the formation and maturation of bone stem cells. In addition, vitamin D regulates the absorption of calcium in the intestine and promotes the incorporation of phosphate and calcium in the bones.
The bones become stronger and harder. In addition, phosphate and calcium are components of the teeth.
Vitamin D is also important for other metabolic processes and affects muscle strength.
Other effects are attributed to vitamin D, but these have not yet been clearly scientifically proven.
When should you take vitamin D?
Vitamin D should only be taken as an additional dietary supplement in exceptional cases in consultation with your doctor .
How do I recognize a vitamin D deficiency?
A vitamin D deficiency can manifest itself in a number of ways. We have listed some possible symptoms here:
- hair loss (9)
- increased susceptibility to infection (10)
- disturbed bone mineralization (rickets in children, osteomalacia in adults) with bone pain and deformities (1)
- Muscle weakness, muscle pain, body aches
- muscle cramps, migraines
Which diseases can occur due to a vitamin D deficiency?
Apart from the vitamin D deficiency symptoms mentioned above, there are much more serious diseases that can be triggered by a vitamin D deficiency.
- cancer (2)
- Respiratory diseases (like asthma) (8)
- Cardiovascular diseases (such as heart attack, stroke) (2)
- Autoimmune diseases (such as multiple sclerosis) (2)
- Metabolic diseases (such as diabetes) (2)
However, it is still largely unclear whether the vitamin D deficiency is the cause or the consequence of one of the diseases mentioned above.
When is the best time of day to take vitamin D?
In this section of the article, we aim to answer any more advanced questions you may have. For one, we answer the question of when? In addition, we clarify other questions that you might ask yourself.
What time of day is best to take vitamin D?
It is important that the intake of vitamin D occurs at the same time as the consumption of foods with a fat content. Because vitamin D is fat-soluble and can best be absorbed by the intestine when dissolved in fat.
Vitamin D can be taken regardless of the time of day.
If other information is given in the package insert of the vitamin preparation, you should follow it in any case.
Who Should Take Vitamin D?
Anyone who cannot meet their vitamin D needs through exposure to sunlight and food should take vitamin D. A study from Germany shows that vitamin D deficiency is particularly pronounced in the months with little sunshine. 30% of the people examined had a severe vitamin D deficiency in the months of January to April.
A 25-vitamin D determination can be used to determine whether there is a vitamin D deficiency. You should definitely have this test done before you start taking vitamin D.
As mentioned above, vitamin D should only be taken in exceptional cases in consultation with your doctor.
What is the best way for the body to absorb vitamin D?
As mentioned above, vitamin D is a fat-soluble vitamin. Therefore, when taking it, care should be taken to ensure that it is taken with food that contains some fat. Vitamin D is best absorbed by the intestine when dissolved in fat.
It is also important to ensure that the body has enough vitamin K, magnesium, calcium and vitamin C.
A deficiency in the substances just mentioned can have an interaction with vitamin D intake.
We go into more detail about the interactions with the question: What should you consider when you take vitamin D?
What should you consider when taking vitamin D?
Magnesium and vitamin C, for example, are needed by the kidneys and liver to form vitamin D. Vitamin K is required for the incorporation of calcium into the bones. If the vitamin K is missing, the calcium is not built into the bones and thus increases the risk of arteriosclerosis. Calcium and vitamin D are therefore directly related.
Vitamin D promotes calcium absorption. If there is not enough calcium when taking vitamin D, the vitamin D will take the calcium from the bone mass. This would have the opposite effect and promote osteomalacia.(1)
What vitamin D supplements are there?
Vitamin D is offered either as a tablet or as drops. It is also possible to buy vitamin D in powder form.
|Vitamin D supplement||Ease of dosing|
|powder form||possibly awkward|
The drops are recommended because they are already dissolved in oil and are thus better absorbed by the intestines.
How helpful is vitamin D for strengthening the immune system?
Vitamin D is important for the innate immune system and the regulation of calcium and phosphate metabolism. The exact mechanisms of action of vitamin D in the immune system are only partially understood and need more research.
However, it can be said that vitamin D is very important for our immune system.(4)
How Much Vitamin D Should You Consume Per Day?
The German Society for Nutrition (DGE) estimates the daily requirement at 20 micrograms of vitamin D. According to the DGE, infants need half that amount.
|Old||Vitamin D intake in the absence of endogenous synthesis (in µg/day)|
|up to 12 months||10|
|1 to 14 years||20|
|15 to 64 years||20|
|from 65 years||20|
Is there any harm in taking too much vitamin D?
An oversupply of vitamin D can manifest itself through various symptoms.
- General weakness and fatigue
- Anorexia, nausea, vomiting, constipation
- Poor concentration, confusion, drowsiness, coma
- Tachycardia, arrhythmia (heart rhythm disturbances)
- Nephrolithiasis (kidney stones), nephrocalcinosis, decrease in kidney function
- Soft Tissue Calcification(1)
Should children also take vitamin D?
Like adults, children should take extra vitamin D if they cannot meet their own daily requirement through food or sun exposure. Vitamin D is particularly important for children during development.
But here, too, you should be careful and only make decisions in consultation with your treating pediatrician.(5)
How long does it take for vitamin D storage to be full?
The amount of vitamin D in the body varies greatly. The main reasons are body size and weight. Another important point is the body fat percentage, since vitamin D can be stored particularly well in fat.
Again, the exact size cannot be determined. We advise you to cover the entire daily requirement in consultation with your doctor.(6)
What alternatives are there to vitamin D supplements?
You can not only get vitamin D from preparations such as drops, powder or tablets. If you can cover your daily vitamin D requirement through your food and sun exposure, we recommend this variant.
- Sun : Your most important source of vitamin D is the sun. According to the Society of Anthroposophic Doctors in Germany (GAÄD), 15 to 30 minutes of sun a day are sufficient to cover the daily vitamin D requirement. Sunscreen should definitely be avoided, as it usually prevents the formation of vitamin D.(7)
- Diet : Food of animal origin contains a lot of vitamin D. Oily fish, such as mackerel, salmon and herring, are particularly good sources of vitamin D. Otherwise, you can find a lot of vitamin D in eggs and dairy products.
|Groceries||Vitamin D content (in µg/per 100g)|
It doesn't matter when you take vitamin D. It's just important that you make sure you're eating something fatty while you're taking it. You should also make sure that you cover your daily vitamin D requirement.
If you can cover your daily vitamin D requirement through sun exposure and diet, you should definitely do so and avoid supplements. If you cannot meet your vitamin D needs in this way, you should definitely consult your doctor and not self-administer a cure.
- It has been found that vitamin D deficiency can lead to osteoporosis and rickets, among other things. Furthermore, symptoms of vitamin D toxicity were found.
- Symptoms of vitamin D deficiency or excess were explained. The study concludes by recommending moderate vitamin D supplementation.
- In a study from 2008-2011 in northern Germany, vitamin D deficiency was found in all age groups. In months with little sunshine, more than 30% of the people examined had a severe vitamin D deficiency.
- Vitamin D has been found to be important in regulating calcium and phosphate metabolism. However, the precise molecular processes are only partially understood.
- 17,641 participants between the ages of 0 and 18 were tested. 63% of the participants were within the limit and only 17% had a normal level. The study concluded that fortifying foods with vitamin D should be considered.
- The study shows that vitamin D is stored in adipose tissue and muscle. There are strong deviations between the determined values.
- Vitamin D can be obtained through sun exposure. The amount of vitamin D is strongly dependent on seasonal fluctuations, time of day and sunscreen.
- The study proves a connection between vitamin D deficiency and the autoimmune disease asthma. Preventive treatment with vitamin D can have positive effects on the disease.
- In the study, experiments were done with rats. The link between vitamin D deficiency and hair growth has been studied. The study found that vitamin D deficiency inhibits hair growth.
- The study found that vitamin D had an antiviral effect. The connection is much more complex than expected. More research will be done in this area in the future.