Vitamin D is essential for the proper functioning of the body. Since it is involved in the absorption of calcium and phosphorus, it helps in the bone mineralisation process. But that’s not all this vitamin does! A lack of it can affect one's mood, and it is also essential for the immune system.Without outside help, the body cannot produce this vitamin on its own. It needs the sun's ultraviolet rays to shine directly onto the skin for it to be produced.Since we have all been confined indoors for weeks now, it is quite possible that the first signs of vitamin D deficiency are appearing more quickly than expected. These signs can be:Feeling overly tired or exhaustedMuscle weaknessDepression Dry skinBone fragilityCrampsIn addition to being unpleasant to live with, these symptoms caused by vitamin D deficiency are also associated with infections, cardiovascular disease, and autoimmune and inflammatory diseases.To avoid this, it's a good idea to adapt your daily routine to ensure that your body receives the minimum dose of vitamin D. Vitamin D in your dietFortunately, it is possible to incorporate vitamin D into your diet since it is present in many different foods. Herring, salmon, sardines, mackerel, trout, canned tuna... In general, fatty fish contain a lot of vitamin D. It can also be found in eggs, milk, soy drinks and dark chocolate (minimum 40% cocoa). If you want an immediate boost, the best option remains cod liver oil…Vitamin D in food supplementsIf you’re feeling down because of being stuck inside, you are likely to be lacking in vitamin D. Once you have adapted your diet to add this vitamin, you can then turn to dietary supplements. In capsule or liquid form, it is advisable to take them during, or at the end of a meal for optimal absorption.Vitamin D through the windowNo balcony or garden? 10 to 20 minutes in front of your window will be enough to produce vitamin D in the spring or summer. However, during the winter, about 2 hours will be necessary. The higher the sun is in the sky, the more UV rays it produces, so make sure to be exposed near your window between 12 pm and 2 pm. And don't forget the sun cream!