People are being urged to consider taking a supplement in the winter months to ensure they get enough vitamin D.
In a raft of new guidance, Public Health England (PHE) in the UK said vitamin D was vital for bone and muscle health but that people were generally not getting enough from sunlight during the winter months.
It said everyone should ensure they were getting 10 micrograms of vitamin D per day, and should consider a supplement, and breastfed babies and young children must be given a supplement to boost their intake.
Babies under one who are exclusively or partially breastfed should be given a supplement containing 8.5 to 10 micrograms of vitamin D per day.
Babies who are formula fed and drink at least 500ml of formula a day are already getting enough vitamin D from the mixture.
Children aged one to five should receive a daily supplement containing 10 micrograms of vitamin D.
Everyone over the age of five, including adults, who has a balanced diet with oily fish and are exposed to sunlight, should be getting enough vitamin D in the summer. But people should consider taking a vitamin supplement from October to March to ensure they are receiving enough.
Some groups of people with very little or no sunshine exposure should take a supplement all year round.
These include frail or housebound people, such as those in care homes, and those who wear clothes that cover most of their skin while outdoors, such as for religious reasons.
People from minority ethnic groups with dark skin such as those of African, African-Caribbean and South Asian origin should also consider taking a supplement every day of the year.
Advice already exists to say pregnant and breastfeeding women should take a daily dose of vitamin D.
The new recommendations are based on advice from the Scientific Advisory Committee on Nutrition (SACN), which was asked to review the evidence by the Department of Health.
The recommendations refer to average intake over a period of time, such as a week, and take account of day-to-day variations in vitamin D intake.
Sunlight is the main source of vitamin D for most people, but the SACN was unable to say how much sun was the “right amount”, owing to differences in how people’s bodies convert vitamin D.
The vitamin is also found naturally in a small number of foods such as oily fish, red meat, liver and egg yolks, and is added to some breakfast cereals and spreads.
Some of the best sources are eggs (one whole poached egg contains 1.025mcg of vitamin D) and fish (one 112g fillet of mackerel contains 18mcg, an 85g fillet of cooked salmon cooked contains 11.2mcg and 85g of tinned, drained salmon contains 12.3mcg).
Dr Louis Levy, head of nutrition science at PHE, said: “A healthy, balanced diet and short bursts of sunshine will mean most people get all the vitamin D they need in spring and summer.
“However, everyone will need to consider taking a supplement in the autumn and winter if you don’t eat enough foods that naturally contain vitamin D or are fortified with it. And those who don’t get out in the sun or always cover their skin when they do, should take a vitamin D supplement throughout the year.”
The main function of vitamin D is to regulate calcium and phosphate, which are vital for healthy bones, teeth and muscles.
Experts have become concerned in recent years that rickets is re-emerging in children who do not get enough vitamin D.
This includes youngsters who are always covered in sunscreen during the summer months and are not exposed to sunlight. In adults, a lack of vitamin D can cause bone pain and tenderness.