What is vitamin d vitamin d is an essential nutrient that is needed for the body to absorb calcium and phosphorus. These two minerals play a vital role in the growth and maintenance of strong bones and teeth. It's also proven to support the immune system and healthy muscle function. Vitamin d is rare in natural food sources, and your main source is likely to come from the sun's rays. As many as two-thirds of adults in the uk do not receive the recommended levels of vitamin d. Simply supplements has designed this carefully formulated supplement to help you ensure a sufficient vitamin d intake. Should i add vitamin d supplements to my diet current official advice is that all adults should consider taking a vitamin d supplement. As skin ages, it becomes less efficient at converting the sun's rays into usable vitamin d. Vitamin d supplementation supports normal bone health whilst a deficiency may cause bones to become weaker, making them more susceptible to fractures and breaks. Quality-assured vitamin d tablets simply supplements work with industry-leading suppliers to obtain the finest quality vitamin d2 ingredients for use in this supplement, ensuring that you receive the best care and support. This 400iu strength supplement is the ideal dosage for healthy adults who wish to maintain an optimal daily vitamin d level. This premium grade, high strength supplement uses plant-derived vitamin d, making the supplement suitable for vegetarian and vegan customers. In an effort to ...