Sunshine, not food, is where most of your vitamin D comes from. So even a healthy, well balanced diet, that provides all the other vitamins and goodness you need, is unlikely to provide enough vitamin D. So with April around the corner it is time to start stocking up again!   What is vitamin D? You make vitamin D under your skin when you are outside in daylight, which is the reason vitamin D is sometimes called the ‘sunshine vitamin’. A vitamin is something that helps our body function – a ‘nutrient’ – that we cannot make in our body. Vitamin D is different because even though we call it a vitamin, it is actually a hormone and we can make it in our body.   What does vitamin D do in my body? Vitamin D works with calcium and phosphorus for healthy bones, muscles and teeth. The Scientific Advisory Committee on Nutrition (SACN) report Vitamin D and Health (July 2016) highlights the importance of vitamin D in protecting muscle strength and preventing rickets, osteomalacia and falls. Even if you have a calcium-rich diet, without enough vitamin D you cannot absorb the calcium into your bones and cells where it is needed. Vitamin D may have other important roles in the body, but there isn’t enough evidence at the moment to make any conclusions.   What happens if I don’t get enough vitamin D? Some babies are born with low levels of vitamin D and some do not get enough in breast milk; this can result in fits or rickets. Older children who do not get enough vitamin D can also develop rickets. Rickets can cause permanent deformities to the bone, weaken muscles and reduced growth. Adults who don’t get enough vitamin D can develop osteomalacia. This makes the bones softer as the minerals needed to keep them strong cannot get into the bone. People with osteomalacia experience bone pain and muscle weakness.   The main source of vitamin D is exposure to sunlight It is the sun’s ultraviolet rays that allow vitamin D to be made in the body. You do not have to sunbathe to make vitamin D. In the UK and Ireland, from October to March the sun is too weak for the body to make vitamin D – even if we spend time outside on bright winter days, it won’t boost our levels of vitamin D. As a result, we rely on the amount we made and stored in the summer. However strong sun also burns skin so we need to balance making vitamin D with being safe in the sun - take care to cover up or protect your skin with sunscreen before you turn red or get burnt. In the winter months we need to top up our levels with foods that contain good amounts of vitamin D and, in some cases, take a supplement. Which foods contain vitamin D? The following are considered to be vitamin D rich foods, • oily fish such as salmon, sardines, pilchards, trout, herring, kippers and eel contain reasonable amounts of vitamin D • cod liver oil contains a lot of vitamin D (don’t take this if you are pregnant) • egg yolk, meat, offal and milk contain small amounts but this varies during the seasons • margarine, some breakfast cereals, infant formula milk and some yoghurts have added or are ‘fortified’ with vitamin D   Vitamin D supplements: A supplement only needs to contain 10 micrograms to meet the recommendation – those with a higher content of vitamin D are unnecessary and could be harmful in the long run. Taking a vitamin D supplement as well as eating foods rich in vitamin D and spending a lot of time outside in sunshine is not a problem. However do not take more than one supplement containing vitamin D (count cod-liver oil as a supplement) as you could exceed the 10 micrograms recommendation. Always choose a supplement tailored to the age group or condition, as fish liver oils and high dose multivitamin supplements often contain vitamin A, too much of which can cause liver and bone problems, especially in very young children, and the elderly. If you are concerned you are not getting enough vitamin D or what the best type of supplement is for you, speak to your doctor, health visitor, or ask to be seen by a dietitian.