Reference values for serum levels of vitamin B₁₂and folic acid in a population-based sample of adults between 35 and 80 years of age

Abstract

Objectives: To examine folic acid and vitamin B 12 status in a group of 1000 persons sampled from the community of Umeå, Sweden, and aged 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80 years. Reference data for folate and age-stratified reference data for vitamin B 12 are presented, together with an examination of potential confounders. Measurements: All subjects participated in extensive health examinations and interviews, and laboratory blood testing was performed. Results: A series of exclusion criteria were applied, and data from 961 subjects were analysed. Vitamin B 12 levels were found to decrease with increasing age, whereas folate levels remained constant across the age span studied. None of the vitamins was found to vary with sex, education, smoking or alcohol consumption, body mass index, prescription-free vitamin supplements, level of haemoglobin, or mean cell volume of erythrocytes. Further, none of these factors was associated with the agerelated decrease of vitamin B 12 level. Conclusions: The offered reference ranges should be used only in order to rule out deficiency. For B 12 levels, the age of the subject should be considered such that, for elderly people in particular, values above the medians should be considered as indicative of normal vitamin status.

Relation of body mass index to blood folate and total homocysteine concentrations in Japanese adults

“…Our findings on the relationship between BMI and plasma folate are consistent with those reported by others [4-10, 12-14, 19]. In contrast, there have been reports indicating that no such association exists [2,3,11]. Both our data and those in the literature are summarized in Table 2, where we limited the number of citations to only those where the subjects were subdivided into more than two BMI groups [4-6, 8,13].…”

“…One of these factors is body-mass index (BMI) that has been suggested to be negatively correlated with plasma/serum folate, although the findings are controversial [2][3][4][5][6][7][8][9][10][11][12][13][14]. For erythrocyte folate, another commonly used index of folate status, however, no such significant correlation are reported [4,5].…”

Plasma folate, vitamin B12, and homocysteine and prostate cancer risk: A prospective study

“…However, a study by Wahlin et al 19 determining reference values of plasma folate and vitamin B12 in a random sample from the same population as ours (and employing the same laboratory techniques) reported no association between supplement use and either folate or vitamin B12 in plasma. That our findings might reflect confounding of a high status of some other vitamin or mineral due to supplement use is therefore unlikely.…”

Cobalamin Status and Its Biochemical Markers Methylmalonic Acid and Homocysteine in Different Age Groups from 4 Days to 19 Years

“…Median serum cobalamin decreased markedly after birth (median, 314 pmol/L) to reach a nadir (median, 217 pmol/L) between 6 weeks and 6 months (P Ͻ0.001). Thereafter, serum cobalamin increased to a maximum concentration at ϳ3-7 years, after which the median concentration gradually decreased toward the concentrations observed in adults (24 ). The period of low serum cobalamin was associated with a marked increase in plasma MMA (from a median of 0.29 to 0.78 mol/L; P Ͻ0.001) and a slight increase in plasma tHcy (from a median of 6.22 to 7.47 mol/L; P Ͻ0.001) and serum folate (from a median of 27.0 to 31.6 nmol/L; P ϭ 0.02; Table 2).…”