Vitamin D is important for the health of bones, muscles and teeth because it helps regulate the amount of calcium and phosphate in the body. It is made in the skin when it is exposed to direct sunlight, but in the UK the rays are not strong enough between October and early March for this to happen. In addition, this year many people have spent much more time indoors than usual due to the pandemic. Therefore, supplementation is recommended for many groups:

• Babies from birth to one year should take 8.5-10mcg (340-400 iU) vitamin D daily throughout the year if breastfed, or formula fed and having less than 500ml of infant formula per day – this is because formula is already fortified with vitamin D
• Children aged one to four years should take 10mcg (400iU) per day throughout the year
• Children over the age of four years, young people and adults – including women who are breastfeeding or pregnant – should take 10mcg (400iU) between October and early March because people do not make enough vitamin D from sunlight during these months
• Children aged over four years, young people and adults should take 10mcg (400iU) throughout the year if they get little sunshine exposure – for example, because they are not often outdoors, or usually wear clothes that cover up most of their skin when outdoors – or if they have darker skin as they may not make enough vitamin D from sunlight.