In the UK there is a rolling programme of conducting nutritional surveys which was established in the early 1990s. Four surveys have so far been conducted as part of the National Diet and Nutrition Surveys. They have each been conducted using representative samples drawn from the British population. People in Northern Ireland were not included in these surveys.
The four NDNS surveys and the year(s) of their publication are:
The findings of each survey have been published and they provide information on:
The surveys excluded people based in hospital, those of no fixed abode and probably severely ill people living at home.
Thus the prevalences observed in these samples may be less than those observed in patients consulting with their doctor or a therapist.
Deficiency is defined in this section as either:
In practice if either of these figures exceeds the figure of 3% in the populations studied then it is likely that there will be some public health consequences.
The NDNS did not include any assessment of the possible impact of deficiency on the health of participants in the survey.