You probably know that we need vitamin D for healthy bones. But do you know its other roles and that your genes can influence its optimal levels? It’s time you meet this important nutrient properly.
Vitamins are essential micronutrients – substances our bodies can’t produce but need in small quantities. Out of all the vitamins, vitamin D is perhaps the most intriguing, because our bodies can make it – with a little help from the Sun!
What are the benefits of vitamin D?
Not many people know that the so-called sunshine vitamin is not even technically a vitamin, but rather a hormone, or specifically, its precursor – a prehormone.
It was first identified as a vitamin early in the 20th century but is now recognized as a prehormone due to its effects, which are stimulated by the same mechanisms as other steroid hormones. However, it does function as a vitamin, so the scientists let it stay among vitamins.
To produce vitamin D, our bodies need sunlight and one other component. Remember cholesterol, an important fat with many functions? It turns out one of them is helping make a vitamin.
Under the influence of UVB light, cholesterol in our skin is converted to previtamin D. We say previtamin because, at this point, it is still inactive and must undergo two changes in our liver and kidneys. Then it is ready to get to work and help our bodies maintain:
- Strong bones: vitamin D promotes calcium absorption and ensures proper levels of calcium and phosphorus in your blood. Both minerals are crucial for bone mineralisation, ensuring strong bones and teeth.
- Normal muscle function: ensures stability, muscle strength, and good physical performance.
- Effective immune system: vitamin D activates your body’s T-cells, responsible for identifying and attacking pathogens.
Lack of vitamin D results in incorrect growth and healing of bones, tiredness, muscle weakness and cramps, rickets in children and osteoporosis in adults.
Sources of vitamin D: Sun, food, and supplements
Sun is the best source of this nutrient. World Health Organization recommends exposing our arms and legs to sunshine for 5 to 15 minutes, between 10 a.m. and 3 p.m., 2–3 times a week. This ensures a sufficient amount of vitamin D.
You might not get enough vitamin D in winter, if you are living far from the equator, are overweight, older, or have dark skin. In those cases, you need to consider the alternatives for maintaining normal levels: food and supplements.
There is only a handful of foods containing vitamin D: oily fish (salmon, tuna, mackerel), dairy, egg yolk, and liver. But there is an abundance of foods fortified with vitamin D (breakfast cereals, yoghurt). In the USA and Canada, for example, all milk is fortified with vitamin D.
There is also a wide range of dietary supplements to choose from – from fish oil capsules to vitamin D sprays.
Vitamin D promotes healthy skin
Vitamin D regulates cell growth, reduces inflammation, and increases skin’s elasticity by stimulating the production of collagen. It also helps with many skin conditions such as eczema, psoriasis, acne, rosacea etc.
But the sun doesn’t only replenish your vitamin D reserves but can lead to serious skin damage. So during the hot summer, use sunscreen, and limit direct sun exposure to no more than half an hour between 11 a.m. and 3 p.m.
Your genes can help predict your level of vitamin D
Besides sun exposure and diet, there is a genetic component to how much vitamin D our bodies produce. Scientists have discovered three genes which are linked with vitamin D levels: GC, DHCR7, and CYP2R1.
Every second individual is predisposed to lack of vitamin D. Finding out if you are among them is easy with our DNA test, which analyses all three relevant genes, and gives you personal recommendations based on your results.
We think about vitamin D more often during winter months when seeing the sun is almost a special occasion, but our genes can contribute to an increased need for this nutrient.
If you discover that you are genetically predisposed to lower levels of vitamin D, you can now pay more attention to nutrition or even grab a supplement to make sure your bones – and entire body – stay healthy.