Nutritional deficiency is widespread
As you read the following, bear in mind that the deficiencies highlighted are against the official RDAs/RNIs, NOT against the optimum levels for the nutrients involved.
The UK National Diet and Nutrition Survey (NDNS), published in 2016, shows that:
Fruits and vegetables
Only 8% of teenagers ate 5 portions of fruits and vegetables a day. The average for teenagers was 2.6.
The average for adults is just under 3.
The American Cancer Society recommends 9 portions of fruits and vegetables a day.
Vitamins and minerals, particularly vitamin D
At least 20% of teenagers are below the RDA /RNI level for vitamin A, B2, calcium, magnesium, iodine, selenium and zinc.
Blood levels of vitamin D in the winter are well below the new RNI levels for the USA and far below the optimum levels that researchers recommend.
An alarming 48% of girls and 27% of women are deficient in iron.
Average intake of fibre across the whole population is 50% the new recommended intake of 30g (one ounce) a day.
Average intake of oily fish is well below the minimum recommendation of 1 portion a week – and researchers are now recommending 2-4 a week.