Do I need vitamin D supplements?
How do we get vitamin D?
Recently, there has been a lot of discussion about vitamin D and the possible need for supplements. Vitamin D belongs to a group of fat-soluble vitamins. Vitamin D3 and, to some extent, vitamin D2 are those that humans use. Vitamin D3 is the type that we can form ourselves or get via animal-based foods, while vitamin D2 comes from plant-based foods. We can get vitamin D through a diet that includes oily fish such as salmon, mackerel, and herring. Meat, cheese, eggs, and some mushrooms also contain some vitamin D. Some foods, such as milk, plant-based milk, and margarine, may be fortified with vitamin D. What’s special about vitamin D is that it can also be formed in the skin when we expose it to the sun’s ultraviolet rays.
Strengthens our bones, teeth, and immune system
The most important job that vitamin D performs in the body is to regulate calcium and phosphate uptake and contribute to the formation and maintenance of strong bones and teeth. Vitamin D also plays a role in our immune system. Studies in laboratories and on animals have shown that vitamin D can reduce the growth of cancer cells. In humans, it has been possible to see a connection between different types of cancers, in particular colon cancer, and low levels of vitamin D. Vitamin D also contributes to the formation of an enzyme in our lungs that is believed to strengthen the immune defence of the lungs and protect us from viruses and bacteria, thus reducing the risk of damage to the lungs. This is one of the reasons why it has been discussed whether low levels of vitamin D contribute to more severe COVID-19 infections, which is why some countries are recommending the use of supplements. However, there is currently insufficient scientific support for vitamin D supplements being able to reduce morbidity in relation to COVID-19. Researchers have found that vitamin D can counteract inflammation, and it has been seen that several different types of cells are receptive to the vitamin.
The sun and vitamin D
This vitamin has a unique function, as vitamin D3 can be formed when the skin is exposed to ultraviolet sunrays (UVB). Because vitamin D is fat-soluble, the body can store it for use later on. To form the vitamin, it is recommended that you expose your arms, legs, upper body, or hands to light for about 15 minutes a day, a couple of days a week during the sunniest months. If you have darker skin, this process takes a little longer. Various factors contribute to reduced levels of vitamin D in the body, such as:
Where you live. In Scandinavia and in more northern latitudes where we have short summers and long winters, the risk of vitamin D deficiency is higher as we don’t get enough UVB rays.
Lack of outdoor activity.
Sunscreen can reduce the formation of vitamin D by 90 percent. Here, however, it’s important to point out that it’s shorter periods without sunscreen that are needed. It’s important to use sunscreen from April to September, in the form of both suncream and clothing if you spend a lot of time in the sun or burn easily. Sun-induced cancer is on the rise due to changing tanning habits, which is why it’s important to protect yourself.
Clothes, especially if they cover the whole body.
Skin type. Darker skinned people need longer in the sun than fair-skinned people, because melanin reduces the formation of vitamin D.
Age. Older people form smaller amounts of vitamin D, especially over the age of 75.
Some types of medication can also affect the breakdown of vitamin D.
Is vitamin D deficiency common?
Globally, it’s relatively common to have a vitamin D deficiency, especially if you belong to one of the groups mentioned above and you don’t eat fish and/or foods fortified with vitamin D. People with inflammatory bowel diseases who may have problems absorbing fat from their diet, people with a certain type of liver disease, and overweight people may also have lower levels of vitamin D. The most common symptom of a long-term and pronounced deficiency is rickets in children, which results in fragile and deformed bones, while in adults osteomalacia (or soft bones) may occur. Symptoms such as muscle pain, weakness, and depression are signs of a less pronounced vitamin D deficiency. In the 1930s, people began adding vitamin D to milk, which resulted in rickets becoming less of a widespread problem in the world. However, vitamin D deficiency, especially minor deficiency known as subclinical deficiency, is a global problem. Research varies, with a lot being done to study the effect vitamin D deficiency can have in the development of a number of different diseases, such as an increased risk of cardiovascular disease and some types of cancer. This in turn leads to discussions regarding the recommended values for vitamin D. At present, a general testing of the population for vitamin D deficiency is not recommended. Instead, targeted testing is recommended for those who belong to an at-risk group. The Swedish Food Agency recommends that the following groups take vitamin D supplements throughout the year, possibly with a break between April and August for those who spend time in the sun:
All children under the age of 2
All adults over the age of 75
Anyone who does not eat fish or foods fortified with vitamin D
Anyone who is not exposed to sunlight in the summer
Is too much vitamin D dangerous?
The body is fascinating and a lot hinges on various balances between hormones, neurotransmitters, and other substances. This is one reason why we should not take certain supplements unnecessarily. It is important to understand that more does not necessarily mean better. Many vitamins and other substances are part of delicate interactions. Having too high a level of a substance can have an adverse effect on another. Trends that recommend high doses of various nutrients should therefore be avoided. When it comes to vitamin D, you can’t have too much, either from your food or from sunlight. However, if dietary supplements are your primary source, this can result in excessive levels of calcium in the blood, which can damage the kidneys and, in a worst-case scenario, lead to kidney failure. Excessive levels of vitamin D can also cause anorexia, weight loss, an irregular heartbeat, and, in the worst-case scenario, damage to the heart. For this reason, you should take supplements only if you need to maintain normal levels of vitamin D.
My advice:
It’s easy to check your level of vitamin D with a simple blood test. If you belong to an at-risk group, you can ask your GP to check this test. To reduce the risk of vitamin D deficiency, it’s a good idea to regularly eat oily fish, as well as eggs and yoghurt, if you’re not vegan. During the sunnier months of the year, remember to expose your arms, legs, or hands to sunlight without sunscreen for around 15 minutes at a time if you’re fair-skinned, and a little longer if you have darker skin.
