{"id":37189,"date":"2016-08-09T09:35:40","date_gmt":"2016-08-09T08:35:40","guid":{"rendered":"https:\/\/blogs.bmj.com\/bmj\/?p=37189"},"modified":"2016-08-09T11:03:59","modified_gmt":"2016-08-09T10:03:59","slug":"hilary-powers-when-to-take-vitamin-d-supplements","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/bmj\/2016\/08\/09\/hilary-powers-when-to-take-vitamin-d-supplements\/","title":{"rendered":"Hilary Powers: When to take vitamin D supplements"},"content":{"rendered":"

\"HP_S_Nov2012In late July 2016 the Scientific Advisory Committee on Nutrition<\/a> (SACN) and Public Health England<\/a> (PHE)\u00a0announced new recommendations on vitamin D. SACN reviewed the evidence at the request of the\u00a0Department of Health<\/a>, which\u00a0asked whether the previous recommendation, that most people would\u00a0get enough vitamin D from sunshine alone, was still appropriate.<\/p>\n

Some people have asked whether\u00a0the review was because there has been an increase in rickets in recent years but in fact levels remain\u00a0low<\/a>.<\/p>\n

SACN found it was not possible to recommend how long we need to spend in the sun to achieve\u00a0adequate vitamin D blood levels as there are a number of factors that affect skin synthesis of vitamin\u00a0D.<\/p>\n

The committee concluded, therefore, that everyone needs a daily dietary intake of 10 micrograms (mcg)\u00a0throughout the year to protect musculoskeletal health. The recommendations assume minimal\u00a0sunshine exposure and refer to average intake over a period of time, such as one week, and take\u00a0account of day-to-day variations in vitamin D intake.<\/p>\n

SACN also considered whether there were any associations between vitamin D intake and other\u00a0health outcomes such as diabetes, heart disease, and cancer, but found there was insufficient\u00a0evidence to make any recommendations.<\/p>\n

PHE data show that in late spring and summer average population vitamin D blood levels are much\u00a0higher than in autumn and winter. This is because there are not enough UVB rays in sunlight to\u00a0produce vitamin D in the skin from October to the end of March, so people have to rely on foods\u00a0that naturally contain or are fortified with vitamin D.<\/p>\n

This led PHE to make the public-facing\u00a0recommendation that people should consider taking a daily 10mcg supplement in the autumn and\u00a0winter if they don\u2019t eat enough food containing or fortified with vitamin D. These foods are oily fish,\u00a0red meat, eggs, liver, and fortified breakfast cereals and low fat spreads.<\/p>\n

To get 10mcg of vitamin D daily from the diet can be difficult. Oily fish is the best food source of\u00a0vitamin D; a 150 gram portion of mackerel contains 12.3mcg of vitamin D and a 170 gram portion of\u00a0salmon contains 13.3mcg. While a boiled egg contains 1.6mcg and a 30 gram bowl of fortified cereal,\u00a0preferably lower sugar, contains 1.4mcg.<\/p>\n

It is especially important for those at risk of vitamin D deficiency to take a daily 10mcg vitamin D\u00a0supplement throughout the year, whatever the weather. These groups are people who are\u00a0housebound, in care homes for example, or always cover their skin when outdoors.<\/p>\n

People with dark\u00a0skin from African, Afro-Caribbean, and South Asian backgrounds should also consider taking a 10mcg\u00a0supplement all year round.<\/p>\n

Babies and young children are a vulnerable group, and while official advice continues to be to\u00a0exclusively breastfeed for the first six months, as a precaution babies from birth until one year should\u00a0be given 8.5 to 10mcg vitamin D drops daily.<\/p>\n

From one year up to and including age four, children\u00a0should be given 10mcg vitamin D drops daily. If babies are fed over 500ml of formula each day, they\u00a0don\u2019t need the drops, as formula is already fortified with vitamin D.<\/p>\n

Doctors and other health professionals are well placed to advise whether patients should take a\u00a010mcg supplement as they can consider whether they are in an at-risk group and help the patient\u00a0look at their diet.<\/p>\n

Vitamin D supplements are affordable\u2014a year\u2019s supply costs less than ten pounds. If you\u2019re eligible,\u00a0you can get them on prescription free of charge. Some women and children in low income families\u00a0may also be eligible for free supplements through the government\u2019s Healthy Start<\/a> scheme.<\/p>\n

These new recommendations don\u2019t mean we should stop wearing sunscreen. People can get enough\u00a0vitamin D by having short bursts in the sun, so a brief walk outside for example. But it\u2019s important\u00a0for sunbathers or people spending long periods of time in the sun to protect their skin and cover up\u00a0before skin reddens or burns, to reduce the risk of skin cancer.<\/p>\n

In summary, the people who should take a daily vitamin D supplement are those who don\u2019t go\u00a0outside, always cover their skin, have dark skin or are 0 to 4 years old. For the rest of us, it depends\u00a0on whether we get outside for short bursts of sunshine and eat enough food containing or fortified\u00a0with vitamin D. If not, then a supplement is something to consider in autumn and winter.<\/p>\n

Take a look at the NHS Choices<\/a> page on vitamin D for further information.<\/p>\n

Professor Hilary Powers<\/strong>\u00a0is chair of the SACN vitamin D working group and professor of\u00a0nutritional biochemistry at the University of Sheffield.<\/p>\n

Competing interests:\u00a0<\/strong><\/p>\n