It is estimated that up to 75% of the world’s population is deficient in Vitamin D. Its main contribution is to our bone health. Most Vitamin D is got from UVB rays from sunlight – in Ireland we only get these in the summertime so a lovely sunny winter day will not replenish us. Food sources include herring, mackerel, salmon, oysters, cottage cheese, eggs and fortified foods (read the packaging to see if it has been added).
However, it is difficult to get enough Vitamin D from food alone, so it is recommended that we supplement from October to March every year. For those who are housebound year-round supplementation is required. If you’re getting blood tests done ask for Vitamin D to be measured so you know where you stand. If you’re supplementing check that its D3 (D2 is less bioavailable and therefore less useful to you). You will see that many supplements have 2,000IU or more. The safe upper limit of Vitamin D from all sources is 4,000IU for adults. It is possible to take in too much when using supplements so exercise caution.