MRC Elsie Widdowson Laboratory

Blood folate status for the UK now published as part of NDNS

Today, Public Health England published the latest blood folate results from the National Diet and Nutrition Survey (NDNS) rolling programme for the UK. The report covers folate results for the UK as a whole and separately for Scotland, Northern Ireland and Wales, based on analysis of blood samples collected over four years 2008/09-2011/12 (2009/10-2012/13 for Wales).

HNR provides the scientific lead for the NDNS; the survey is carried out in collaboration with NatCen Social Research and, for this period, the University College London Medical School.

chard nitrates

Leafy green vegetables are high in folate. Credit: Samantha Forsberg Flickr

Folate in the diet comes from naturally occurring folates in foods, such as green leafy vegetables and brown rice, and folic acid from fortified foods, such as some breakfast cereals, and from dietary supplements. Folic acid is important for pregnancy, as it can help to prevent birth defects known as neural tube defects, including spina bifida. For more information about folic acid and pregnancy, please visit the NHS website.

Two measures of blood folate are reported: serum total folate, which reflects recent dietary intake, and red blood cell folate, which reflects longer term body stores and is generally considered the better measure of long term status. Results for both red blood cell and serum total folate are compared with the World Health Organization (WHO) thresholds indicating biochemical folate deficiency.

Key findings

Women of child-bearing age

  • For women of childbearing age (16 to 49 years) in the UK as a whole, 11.3% had a red blood cell folate concentration below the WHO threshold indicating biochemical deficiency while 16.5% had a serum total folate concentration below the threshold indicating biochemical deficiency.
  • Mean red blood cell folate concentrations were significantly lower in younger women (16 to 24 years) than older women of child-bearing age (35 to 49 years). In the 16 to 24 year age group, 15.6% of women aged 16 to 24 years had a red blood cell folate concentration below the WHO threshold and 22.1% had a serum total folate concentration below the WHO threshold, both higher than for the group as a whole.

Other adults

  • The proportion of other adults with a red blood cell folate concentration below the WHO threshold was 6.8% of men and 8.6% of women aged 19 to 64 years and 7.3% of men and 10.8% of women aged 65 years and over.
  • For serum total folate 15.5% of men and 13.9% of women aged 19 to 64 years and 8.5% of men and 12.4% of women aged 65 years and over fell below the WHO threshold indicating biochemical deficiency.

Children

  • In the 4 to 10 years age group, 1.6% of boys and 5.9% of girls had a red blood cell folate concentration below the WHO threshold and 2.6% had a serum total folate concentration below the WHO threshold.
  • In the 11 to 18 years age group, 9.3% of boys and 19.7% of girls had a red blood cell folate concentration below the WHO threshold and 16.9% of boys and 21.8% of girls had a serum total folate concentration below the WHO threshold.

Scotland

  • Mean red blood cell folate concentration was significantly lower in Scotland than in the UK as a whole for women aged 19 to 64 years and men and women combined aged 65 years and over. 13.9% and 16.5% of these age groups respectively had concentrations below the WHO thresholds, compared with 8.6% and 9.3% in the UK as a whole. 14.8% of women of child-bearing age (16 to 49 years) in Scotland had a red blood cell folate concentration below the WHO threshold.
  • Mean serum total folate concentration was significantly lower in Scotland than in the UK as a whole for women of child-bearing age (16 to 49 years), women aged 19 to 64 years and men and women combined aged 19 to 64 years. 24.4% of women of child-bearing age in Scotland had a serum total folate concentration below the WHO threshold, a higher proportion than for the UK as a whole (16.5%).

Northern Ireland

  • Mean red blood cell folate and serum total folate concentrations were significantly lower in Northern Ireland than in the UK as a whole for women of child-bearing age (16 to 49 years), women aged 19 to 64 years and men and women combined aged 19 to 64 years. The proportion of women of child-bearing age in Northern Ireland with red blood cell and serum total folate levels below the WHO threshold indicating biochemical deficiency was 20.2% and 30.6% respectively, higher than in the UK as a whole (11.3% and 16.5% respectively).

Wales

  • There were no significant differences between mean red blood cell and serum folate levels in Wales and those in the UK as a whole, except for adults aged 65 years and over in Wales who had a significantly lower mean serum total folate than in the UK as a whole. The percentages of people below WHO thresholds for biochemical folate deficiency in Wales were similar to the UK as a whole.

For more information and data, see the full report on the UK government website.