• Too much body fat
• Vitamin D supplement without fat in the diet
• A long stay outdoors is not always enough for the production of vitamin D via the skin
• A magnesium deficiency is almost certainly a vitamin D deficiency
• How does zinc affect the absorption of vitamin D?
• Vitamin D absorption decreases with age
• Pay attention to the form of vitamin D contained in a particular supplement
• Multivitamin supplement or pure vitamin D supplement – which one to choose?
• Kidney and liver diseases can significantly reduce the absorption of vitamin D
• summary

Along with ascorbic acid, vitamin D is one of the most commonly purchased dietary supplements in our country. Although, with the gentle help of sunlight, our skin can synthesize this vitamin without major problems, the number of months of the year when suitable conditions prevail is limited. This is of course due to the specificity of the climate in which we live. Despite this, the number of sunny days per year is small and usually falls in late spring and summer. However, regular vitamin D supplementation is recommended for the remaining months. However, it should be borne in mind that its bioavailability does not only depend on the dose taken. There are many factors that can increase its absorption and just as many factors that significantly limit it. In this text, we will focus on the latter group and briefly discuss each of them, as well as their impact on vitamin D absorption.

Too much body fat

It has long been known that too much body fat has a very negative effect on the functioning of our body. We deliberately did not mention excessive body weight, since it can also be caused, for example, by large muscle gains during endurance strength training. On the other hand, excessive accumulation of fat can not only predispose us to the occurrence of many diseases - including lifestyle diseases - but also significantly limit our ability to absorb vitamin D. This mechanism is relatively simple and results simply from the fact that this vitamin is fat soluble. It is worth noting that in order for vitamin D to affect the proper functioning of our body, it must first be released into the blood. Too much fat in the body can cause it to migrate to these tissues and then bind it permanently. This is very unfavorable, since this mechanism applies both to vitamin D, which is supplied in the form of all kinds of dietary supplements, and to vitamin D, which is produced as a result of exposure to the sun on the skin. It has also been shown that obese people are much more likely to be deficient in this vitamin. After all, the incidence is up to 35% higher than in people of normal body weight.

Vitamin D supplement without fat in the diet

As already mentioned, vitamin D belongs to the group of easily fat-soluble vitamins. A common mistake when supplementing this vitamin is the absence or very little presence of fatty acids in the daily diet. The best solution is to reach for it right before you plan to eat a meal that contains even a small amount of this macroelement. In this way we significantly increase the absorption capacity of vitamin D and facilitate its transport into the bloodstream, where it can perform its functions. It is also important to remember that the type of fat used in the meal has virtually no bearing on vitamin D absorption. However, for purely health reasons, it is worth choosing oils of vegetable origin and fatty sea fish - due to the high content of healthy fatty acids from the omega group.

A long stay outdoors is not always enough for the production of vitamin D via the skin

Contrary to appearances, staying outdoors for hours does not guarantee an adequate supply of vitamin D. The fact is that our skin has effective mechanisms to produce this vitamin. However, we often forget that the right conditions are required for this process to take place effectively. Let's remember that due to the geographical location of Poland, the effective synthesis of vitamin D in the skin can take place only from late April to September. In other months of the year, however, it is practically doable. In addition, most of us also forget that it is not enough to simply stand in the blazing sun for a long time, because conditions must be in place for this. First, it's best to be outdoors from around 10 a.m. to 3 p.m. This is when the sun's rays can have the greatest impact on skin production. The presence of clouds is also a very important factor, because even a light cloud greatly affects the efficiency of vitamin D synthesis, as does smog. It has been proven that residents of cities, where smog is a common phenomenon, have a much lower content of this vitamin than, for example, residents of villages or small towns. The level of body discovery along the way is also an important factor. The more skin is exposed to the sun, the more vitamin D we can synthesize. The necessary minimum is about 18% of the body surface, i.e. face, legs and whole arms. Let's add that the use of all kinds of UV radiation filters effectively blocks the production of vitamin D by the skin.

A magnesium deficiency is almost certainly a vitamin D deficiency

Many vitamins and minerals interact with each other through various biochemical processes. Magnesium and vitamin D are no different. After all, these two trace elements have a similar effect on our body. They help strengthen bones, affect immunity and regulate blood pressure. In addition, it is worth noting that magnesium determines the conversion of vitamin D into its active form, which is then used by the body. Therefore, taking large doses of vitamin D in magnesium deficiency makes no sense. Its bioavailability will therefore be extremely low and only a small part of it will be converted to the active form. It has also been proven that vitamin D taken when there is a magnesium deficiency is not only ineffective, but can even be harmful to us. Such studies were conducted on laboratory animals and in a large number of cases such a procedure led to an acceleration of atherosclerotic changes in the coronary arteries, as well as other diseases of the cardiovascular system.

How does zinc affect the absorption of vitamin D?

In order for vitamin D to perform its functions in the body, the presence of zinc is also required. As in the case of magnesium, these two micronutrients share a number of connections and correlations. Finally, it is zinc that enhances the effects of this vitamin. After all, they affect our mood, can prevent depression and protect us from various disease-causing microbes.

Vitamin D absorption decreases with age

Unfortunately, as man ages, the body gradually degrades. Many biochemical processes proceed much more slowly, the ability of tissues to regenerate decreases, and the risk of certain diseases increases. It is no different with the absorption of vitamin D and its production through the skin. Therefore, as a rule, older people need much higher doses of this microelement. After the age of 60 it is about twice as much and after the age of 75 it can be almost 3 times as much. In addition, this effect is amplified by the progressive demineralization of bones with age, which increases the risk of bone fractures and at the same time increases the need for vitamin D.

Pay attention to the form of vitamin D contained in a particular supplement

Vitamin D is just a generic name for many of the chemical compounds in this group. The most popular varieties are vitamin D2 and D3. It is worth noting that the first of them is most often found in products of plant origin, while the domain of the second is animal products. Both types need to be converted into active forms to serve different roles in our body. However, it is worth remembering that vitamin D3 in this case is almost three times more effective than its counterpart. Therefore, it is worth carefully reading the package inserts of the dietary supplements that we use. It is best to choose those where the largest percentage is the D3 form due to the much greater bioavailability and potency of the effects.

Multivitamin supplement or pure vitamin D supplement – which one to choose?

 Recently, all kinds of preparations that contain a lot of vitamins and minerals in one tablet have become extremely popular. In addition, their price is very often even lower than that of their monovitamin counterparts. However, it's worth asking yourself, does it make sense to take a whole bunch of chemical compounds, of which we often only need one? The answer is of course no. The fact is that such preparations contain many different chemical compounds in small doses. In addition, they work most effectively when we are actually deficient in a specific micronutrient. Therefore, targeted supplementation, i. H. one that contains a chemical compound in a capsule is much better. Let's also note that taking many different vitamins and minerals at the same time increases the risk of overdosing on any of them, and therefore we can feel the severe effects later. It is also worth remembering that in such a situation it is very likely that there will be an interaction between them. One of the most popular situations of this type is limiting the absorption of one macroelement by another by fighting for the same receptors, for example in the gut. As a result, it can lead to the fact that one of them is practically unavailable to our body. Therefore, it is best to choose only those supplements that can significantly complement our deficiencies.

Kidney and liver diseases can significantly reduce the absorption of vitamin D

Healthy kidneys and liver are the key organs for the proper absorption of vitamin D. A large part of its metabolism and thus its conversion into the active form takes place in these organs. Let's add that in this case it doesn't matter whether this vitamin was produced by our skin, obtained with food or thanks to the use of various dietary supplements. When either of these two organs isn't working properly, our body has much lower levels of the active form of vitamin D. Therefore, its low levels in the blood can be a signal that it's worth taking care of the health of your kidneys and liver .

summary

We have presented all the connections between various factors and the ability to absorb vitamin D. Because the dose and long hours away from home on sunny days cannot always guarantee us an adequate supply of this micronutrient. Our bodies are quite complex and require different chemical compounds to function properly. Furthermore, they are closely correlated and a lack of just one of them can have a huge impact on the others. This connection is clearly visible, for example, with the vitamin D mentioned above.