Dietary intake among adults with special reference to vitamin B6

To assess the adequacy of the dietary intake in general, and that of vitamin B6 intake especially.

Dietary intake based on 3 d diet-records was assessed among a random sample of the adult Dutch population (the reference group, n = 300) aged 20-79 y, stratified for age and gender and among a group with a low vitamin B6 intake, selected by means of a food frequency questionnaire.

Among the reference group, absolute vitamin B6 intake on average amply met the RDA in all age-gender categories, whereas the adequate level of 20 microg vitamin B6 per gram protein, was on average met by men only. The prevalences of a vitamin B6 intake below the minimum requirement (absolute) of 1 mg/d was 1-11% and below the average minimum requirement of 15 microg/g protein was 5-12% for the various age-sex reference groups. Average intake of folate among women of childbearing age did not meet the recommendation of 400 microg/d for those who want to become pregnant. Average intake of iron and iodine was also below recommended levels among women aged 20-49 y. Both absolute vitamin B6 intake and the vitamin B6/protein ratio calculated with the diet records was lower among the low vitamin B6 groups than among the reference groups, indicating that the preselection of groups with low vitamin B6 intakes on the basis of a food frequency questionnaire was successful. Intake of energy and macro- and micronutrients, as well as a nutrient density of the diet were lower among low vitamin B6 groups than among reference groups.

It is concluded that a low vitamin B6 intake is the result of both the quantity (energy) and quality (nutrient density) of the food consumed. The effects of this are not restricted to vitamin B6 and therefore, the low vitamin B6 groups have a combination of relatively low intakes.