Recommended vitamin D intakes for all of us living in the UK have changed following the publication of a report from the Scientific Advisory Committee on Nutrition (SACN) on 22 July 2016. New guidelines were required because of the persisting problem relating to vitamin D deficiency: cases of rickets and seizures continue to be reported in British infants.
The SACN worked from a range of measures of musculoskeletal health, including preventing rickets and falls in older people to propose that blood levels of 25(OH)D (a blood test that measures vitamin D levels) of <2nmol/l may be defined as deficient. Above this level no significant problems were identified with musculoskeletal health. A daily intake of vitamin D of 10Î¼g (equivalent to 400 international units) is required by all over one year of age in order to reach blood levels above this. Pregnant and lactating women in the past were recommended to take extra vitamin D. The advice is now to take the same 10Î¼g. Those aged under a year require a lower dose of 8.5Î¼g. The SACN guidelines differ from several others, such as those of the European Food Standard Agency or the Institute of Medicine in the United States, which recommend 15Î¼g. Debates will therefore persist, particularly in the marketplace, relating to specific pharmaceutical products and how these can be used to match different targets.
The National Diet and Nutrition Survey recorded that the levels of vitamin D intake in British diets seldom reaches half of the required intake. At the same time our exposure to sunshine is now, in the main, also insufficient. Although there are a number of campaigns to fortify commonly consumed food types, such as milk or bread, this strategy has proved unsuccessful in the UK so far (despite success in several European countries, Canada and the US). The importance of the SACN recommendation is therefore the clear directive for all of us either to change our diets or take a supplement.
However, a number of practical problems have become evident following the release of this SACN guideline. For instance, how is a mother to supplement her breast-fed infant with the correct amount of vitamin D? Are there any more palatable forms of vitamin D supplements for infants and young children? Who is to advise those who have lowest vitamin D levels about supplements? For those of us visiting the local pharmacy for our supplement, we rapidly find a wide variety of commercial products with complex labels. Products in individual pharmacies vary in price and display different types of advice on their labelling. For example, the use of micrograms or hundreds of units on labels has been described as bringing back our worst nightmares of secondary school mathematics.
Reliance on the open market is can be complicated by other factors, too. Some will take large amounts of supplements to the detriment of their health or that of their children (
Clinical Pharmacist 2016;8:131). A case of vitamin D overdose in a child in east London since the SACN recommendation demonstrated that parents thought vitamin D could be taken safely in excess.
Manufacturing accidents can happen. In Denmark earlier in 2016, a new and more palatable form of vitamin D for infants was sold at a strength of 75 times greater than stated on the label, resulting in the admission of six infants with high calcium levels caused by vitamin D toxicity. The problem was rapidly identified and managed at a national level before sales of the product exceeded 290 vials. Would such a reaction be possible in the UK?
The new national guidelines have the merit of being supported by sound musculoskeletal data. Many in our communities require changes to their lifestyles in order to meet its requirements. Now is the time for the pharmaceutical industry to develop safe, well labelled products to meet this need, and a new market.