Nutritional Deficiencies

Vitamin B6 - updated: 24 November 2008

Dietary intake among adults with special reference to vitamin B6

Eur J Clin Nutr. 1997 Nov;51 Suppl 3:S25-31

Brants HA, Brussaard JH, Bouman M, Löwik MR.

OBJECTIVE: To assess the adequacy of the dietary intake in general, and that of vitamin B6 intake especially. DESIGN AND SUBJECTS: 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. RESULTS: 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. CONCLUSIONS: 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.

Publication Types:

• Study

B vitamin status and concentrations of homocysteine and methylmalonic acid in elderly German women

Am J Clin Nutr. 2003 Oct;78(4):765-72

Wolters M, Hermann S, Hahn A.

BACKGROUND: Prior investigations found that elderly persons are at higher risk than are younger persons for B vitamin deficiency, which leads to elevated plasma total homocysteine (tHcy) concentrations that are associated with an increased risk for certain diseases such as coronary artery disease. To date, published data have shown decreased vitamin status and elevated tHcy among the elderly. OBJECTIVE: We evaluated the dietary intake and the blood status of various B vitamins and tHcy and methylmalonic acid (MMA) concentrations in 178 younger (60-70-y-old) female seniors. DESIGN: Dietary intake was assessed with a 3-d diet record. Thiamine, riboflavin, and vitamin B-6 activity coefficients of erythrocyte transketolase (EC 2.2.1.1), erythrocyte glutathione reductase (EC 1.6.4.2), and erythrocyte alpha-aspartic aminotransferase (EC 2.6.1.1) were used as functional indexes for the status of the 3 vitamins, respectively. Concentrations of serum and red blood cell folate, serum cobalamin and MMA, and plasma tHcy were measured. RESULTS: Indexes of thiamine, pyridoxine, and cobalamin indicated insufficient status in one-third of the women, whereas tHcy and MMA concentrations were elevated in 17.4% and 9.6% of the women, respectively. An association between vitamin intake and vitamin concentration in the blood was found only for folate. The mean tHcy concentration in subjects in the lowest quartile of serum folate concentration was 23% higher than that in subjects in the highest quartile. There was no association between riboflavin and tHcy concentrations. MMA was positively correlated with age and inversely correlated with serum cobalamin concentration. CONCLUSIONS: Even in younger, well-educated, female seniors, the prevalence of low B vitamin status and elevated plasma tHcy concentration is high. Thiamine, pyridoxine, folate, and cobalamin supplementation should be considered.

Publication Types:

• Study

B vitamins: proposed fortification levels for complementary foods for young children

J Nutr. 2003 Sep;133(9):3000S-7S

Allen LH.

The B vitamins, except for folate, can be classified as group I nutrients during lactation. Nutrients in this category share the following characteristics: low maternal intake or stores during lactation reduce the concentration in human milk, and infants' stores are readily depleted. For some of these nutrients, the infants' stores at birth may be depleted by maternal deficiency during pregnancy. The prevalence of some B vitamin deficiencies, especially deficiencies of riboflavin and vitamin B-12, is probably much higher than is usually assumed. Taken together, these considerations emphasize the importance of supplying adequate amounts of B vitamins to infants and young children. Recommendations are made here on the amounts and densities of B vitamins that should be present in fortified complementary foods fed to children aged 6-24 mo. The values are based on the difference between recommended daily intakes and the amount that the child will receive from maternal milk using estimates reported in the literature. There are few concerns about the potential toxicity of any of these vitamins at the levels likely to be added to complementary foods. If there are losses during food preparation or concentrations of the vitamins are low in human milk, the estimates provided may need to be inc

Publication Types:

• Review

Rationale, design and methods of a study on micronutrient status among adults

Eur J Clin Nutr. 1997 Nov;51 Suppl 3:S4-11

Löwik MR, Brants HA, Brussaard JH, van den Berg H, Kistemaker C, Hermus RJ.

OBJECTIVE: To describe the rationale, design and methods for a nutrition surveillance study with special reference to vitamin B6 and other micronutrients. RATIONALE AND DESIGN: Several studies in the Netherlands have shown that differences in dietary intake and in nutritional status indicators are relatively small among various socio-demographic groups, so that the relevance of this traditional risk group identification in terms of public health and nutrition policy is limited. Therefore, it was decided to use the diet itself as primary selection criterion for a study on the adequacy of the vitamin B6 supply. The first Dutch national food consumption survey in 1987/88 showed, among other things, that mean vitamin B6 intake (per gram of protein) was substantially below the adequate level for all age-gender groups studied. Since the potential impact on public health of this observation may be relatively large, intake of vitamin B6 was chosen as first selection criterion. A study design that creates the largest possible distinction in vitamin B6 intake would be most efficient to study the health risks as a consequence of a low vitamin B6 intake. Several arguments, such as the need to estimate the prevalence of an inadequate status of vitamin B6 and other micronutrients, led to the decision to use a random population sample as a reference group for comparison with the group with low habitual vitamin B6 intake. Other major arguments underlying the study design and the selection of the nutritional status indicators, as well as the framework of the Dutch Nutrition Surveillance System, are discussed. Finally, the design and methods of the study are described in detail (except food consumption methods).

Publication Types:

• Review

Micronutrient status, with special reference to vitamin B6

Eur J Clin Nutr. 1997 Nov;51 Suppl 3:S32-8

Brussaard JH, Löwik MR, van den Berg H, Brants HA, Kistemaker C.

OBJECTIVE: To assess the adequacy of micronutrient status among the adult population, with special reference to vitamin B6 status. DESIGN AND SUBJECTS: Micronutrient status was assessed among a random sample of the adult Dutch population (reference group, n = 300), aged 20-79 y, stratified for age and gender, and among a group with a low vitamin B6 intake (n = 144). RESULTS: Low vitamin B6 groups had lower mean levels of erythrocyte and plasma pyridoxal (PL) and pyridoxal-5'-phosphate (PLP), urinary excretion of 4-pyridoxic acid, basal and stimulated erythrocyte aspartate aminotransferase (EAST) and erythrocyte alanine aminotransferase (EALT) activities and EAST stimulation coefficients but not of EALT stimulation coefficients, handgripstrength and 24 h homocysteine excretion before and after a methionin load test. Besides, plasma levels of vitamin C, B12 and folate were lower among low B6 than among reference groups indicating a combined low vitamin status. Direct biomarkers of vitamin B6 intake (plasma PLP and 4-pyridoxic acid excretion) were significantly related to more functional parameters (EAST, EALT and alpha-EAST). Among random reference groups the prevalence of plasma PLP values below 19 nmol/l was 3-7% for different age-gender groups, with the highest value of 16% among men aged 50-79 years. The prevalence of high values of erythrocyte glutathion reductase stimulation coefficient (alpha-EGR) and low levels of serum vitamin B12 and C was not more than 5% among different age-gender reference groups. CONCLUSIONS: Direct biomarkers of vitamin B6 intake confirmed the preselection of a group with a low vitamin B6 intake. The results suggest that the sensitivity of vitamin B6 status parameters for low vitamin B6 intake was highest for the direct vitamin B6 status parameters and lowest for handgripstrength and homocysteine excretion after a methionin load; results for enzyme stimulation coefficients were intermediate. The prevalence of below adequate status parameters for vitamin B2, B6, B12 and C was not more than 7% among the different age-gender groups, with the exception of a value of 16% for plasma PLP levels below 19 nmol/l among men aged 50-79.

Publication Types:

• Review

Is vitamin intake by the elderly in The Netherlands precarious?

Ned Tijdschr Geneeskd. 1989 Feb 11;133(6):298-302

Löwik MR, Schrijver J, Westenbrink S, van den Berg H, Brants HA, van der Beek EJ.

The elderly are vulnerable to nutritional risks. The vitamin intake (assessed through dietary history) and vitamin status of 539 independently living persons aged 65-79 years and 44 lacto-(ovo)-vegetarian persons aged 65-97 years were evaluated. All respondents were apparently healthy. Compared with the Dutch recommended dietary allowances the intake of vitamins was assessed as adequate except for vitamin B6. The marginal intake of vitamin B6 is reflected in the vitamin B6 status. The prevalence of low 25-hydroxyvitamin D concentrations in plasma is high among elderly people as compared with younger adults (blood donors); the concentration is negatively correlated with age. The vegetarian elderly appeared to be at risk regarding the vitamin B12 status. In conclusion, the average intake of vitamins is assessed as adequate, whereas the intakes of vitamin B6 and vitamin D of Dutch apparently healthy elderly need more attention

Publication Types:

• Review

Publication Types:

• Review