In July last year, new advice on vitamin D was issued from the UK government. This was a result of the report on Vitamin D from the Scientific Advisory Committee on Nutrition (SACN, 2016).
Everyone over 1 year of age should consume 10 micrograms (µg) or 400 IU (International Units) of vitamin D daily (SACN, 2016). This is particularly important during the winter months. All babies from birth up to 1 year of age should consume 8.5 to 10 micrograms (340-400 IU) of vitamin D per day.
So, are you taking a daily 10 microgram supplement of vitamin D? Below are 10 facts about vitamin D.
Around 1 in 5 adults (aged 19-64 years) in the UK have low vitamin D levels.
Vitamin D is actually not a vitamin but a pro-hormone. There are around 200 genes in our bodies that require vitamin D to function.
Vitamin D is needed to help the body absorb calcium and phosphate from our diet. These minerals are important for healthy bones, teeth and muscles.
Vitamin D has many roles beyond bone health. Evidence suggests that vitamin D could have a beneficial role in a variety of health conditions such as cancers, cardiovascular disease, infectious diseases and autoimmune diseases.
Vitamin D is known as the ‘Sunshine Vitamin’. We are able to make our own vitamin D through sun exposure when outdoors. Most of us need around 15 minutes of sunshine on the face and arms to make enough vitamin D each day.
As a general rule, your body can only make vitamin D when your shadow is shorter than your height. However, in the UK, we can’t make vitamin D between October and March as there’s not enough sunlight. That's why a vitamin D supplement is particularly important to take during the winter months.
In adults, the average daily intakes of vitamin D from the diet range from 2.5 to 5 micrograms a day.
There are very few naturally rich dietary sources of vitamin D. Foods that contain significant amounts are mostly from animal origin. Rich sources include egg yolk and oily fish such as salmon, mackerel, herring and trout. However, less than 1 in 4 people eat oily fish on a regular basis. Red meat also contains vitamin D and some foods and drinks may be fortified with vitamin D (e.g. breakfast cereals, fat spreads and non-dairy milk alternatives).
Cultivated mushrooms usually don’t have much vitamin D as they are grown in the dark, but UV light treated vitamin D enhanced mushrooms are now commercially available.
Taking too much vitamin D supplements over a long period of time can cause more calcium to be absorbed by the body than can be excreted. This leads to high levels of calcium in the blood (hypercalcaemia). Do not take more than 100 micrograms of vitamin D a day as it could be harmful.
SACN (2016) Vitamin D and Health. Available: https://www.gov.uk/government/publications/sacn-vitamin-d-and-health-report
Bates et al, (2016). National Diet and Nutrition Survey. Results from Years 5 and 6 (combined) of the Rolling Programme (2012/2013 – 2013/2014). Available: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/551352/NDNS_Y5_6_UK_Main_Text.pdf
Lanham-New SA, Wilson LR (2016) Vitamin D: has the new dawn for dietary recommendations arrived? Nutrition Bulletin 41, 2-5. Available: http://onlinelibrary.wiley.com/doi/10.1111/nbu.12185/epdf
NHS Choices description of the new Vitamin D recommendations. Available: http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Vitamin-D.aspx