Thousands of people in the UK are at risk of nutrient deficiencies, according to the latest National Diet and Nutrition Survey (NDNS).1 We look at the findings.
Children aged four to 10 years of age are getting just 20 per cent of the recommended daily intake of 10mcg vitamin D from food alone – a figure that rises to only 27 per cent when supplements are included. For teens the intake is 35 per cent when supplements are included and 42 per cent for working age adults. The only group remotely in reach of the recommendation is women aged 65-74 years, 65 per cent of whom reach recommended intakes when supplements are taken into account.
NHS advice is that anyone over the age of four years of age should consider taking a daily supplement containing 10mcg of vitamin D in the autumn and winter months. Supplementation is recommended year-round for infants and at-risk groups such as pregnant and breastfeeding women, the elderly and housebound people, and those who cover their skin for cultural reasons.
Four out of 10 women fail to reach the lower reference nutrient intake (LRNI) for iron. Nine out of 10 women of child-bearing age now have such low levels of folate that if they became pregnant, their child would be at increased risk of neural tube defects.
A quarter (24 per cent) of girls aged 11 to 18 years are not achieving the LRNI for vitamin A and one in eight adults (13 per cent) is also falling short in spite of vitamin A being considered to be reasonably abundant in food. Older adults are the only age group coming close to adequate intakes of vitamin A with nine out of 10 (93 per cent) of over 65s achieving the target intake.
One in 10 adults aged 19 to 64 years have low intakes of vitamin B2, but 14 per cent of women are falling short, compared with 6 per cent of men. One in five teens is not achieving the recommended intake, with the problem worse in girls than boys.
One in five (22 per cent) girls aged 11 to 18 years fail to achieve the target for calcium (an increase of 47 per cent since the first NDNS). Intakes are also falling among boys of the same age, with 16 per cent now failing to meet the target, compared to 11 per cent a decade ago. One in 10 adults (9 per cent) are not getting enough calcium and 11 per cent of women over 65, who are at increased risk of osteoporosis and fragile bones, are falling short.
One in five children aged 11 to 18 years is not reaching the LRNI of iodine, with girls far more likely to be low in iodine than boys (27 per cent compared to 14 per cent). One in eight workingage adults are also not getting enough iodine – an increase of 71 per cent since the first NDNS.
More than a quarter of teenage boys and half of teenage girls are not achieving the LRNI for magnesium. Among working-age adults, 13 per cent are not achieving the target intake and 16 per cent of over-65s are also falling short.
In the case of zinc, children are the most likely group to be lacking this nutrient, while more than a third of teens and working-age adults, and over half of over-65s, fail to achieve the LRNI for selenium.
The average adult intake of oily fish is 56g a week – well short of the recommended 140g. Over 65s ate the most oily fish (an average of 84g per week).
Findings from recent human studies have shown that vitamin D supplementation can improve muscle strength. One study involving nearly 1,000 people found increased 25 hydroxyvitamin D (25 (OH)D) levels were significantly correlated with higher physical activity and a greater hand grip strength.
This has led to interest in examining the effect of vitamin D on sport-specific performance measures. A randomised controlled trial of young women, for example, found that jumping and movement efficiency was substantially increased in the group taking a vitamin D supplement.
Whether vitamin D can reduce the risk of athletic injury has also been of recent interest in the scientific literature. A prospective age-matched cohort study of over 1,000 Royal Marine recruits in the UK found a 60 per cent higher incidence of stress fracture among recruits with low vitamin D levels.
Preliminary studies indicate that probiotics may help weight maintenance or weight loss when combined with an energy restricted diet. Studies are also beginning to suggest that probiotics could reduce the risk of cancer, cardiovascular disease and, independently, also increase life expectancy. Some evidence also suggests probiotics may be useful in preventing cold and respiratory infections in children.