Relationship between methylmalonic acid, homocysteine, vitamin B12 intake and status and socio-economic indices, in a subset of participants in the British National Diet and Nutrition Survey of people aged 65 y and over

Abstract

Objective: Assessment of functional vitamin B 12 status in a subset of the respondents in the British National Diet and Nutrition Survey of people aged 65 y and over. Setting: National Diet and Nutrition Survey: a British nationwide cross-sectional sample of people aged 65 y and over, living either in the community or in institutions such as nursing homes, during one calendar year spanning 1994 -1995. Methods: Methylmalonic acid (MMA) concentrations were measured in plasma samples from 313 subjects (ca 14% of those originally enrolled in the survey). The results were compared with those for serum vitamin B 12 , vitamin B 12 intakes and other status and intake estimates and with socio-demographic indices. Results: Of the NDNS participants overall, 20% had serum vitamin B 12 concentrations < 150 pmol=l. In the subset studied here, 24% of free-living and 46% of institution-living participants had MMA >0.5 mmol=l. Geometric mean MMA increased with age, from 0.25 mmol=l in people aged 65 -74 y to 0.38 mmol=l in people aged 85 þ y. There was little evidence for any gender difference in MMA. It was inversely correlated with serum vitamin B 12 and with red blood cell folate; it was positively correlated directly with total homocysteine, but not significantly with serum folate or with vitamin B 12 intake. Among respondents with high MMA, a subgroup had normal serum vitamin B 12 but higher-than-average plasma urea and creatinine. Socio-demographic co-variates of MMA included receipt of State income benefits, social class of head of household, and educational attainment. These indices were not correlated with serum vitamin B 12 . Conclusions: The progressive increase in MMA with age is metabolic evidence for increasing risk of functional vitamin B 12 deficiency with increasing age in older people. There is evidence that renal function is linked to high MMA in some older people. Age and renal function are thus both important when establishing upper reference limits for MMA. The socio-demographic observations suggest a link between poverty and poor functional vitamin B 12 status in older British people.

Serum vitamin B12 concentrations and atrophic gastritis in older New Zealanders

“…Further, serum concentrations of these metabolites are lowered with vitamin B 12 therapy even when serum concentrations of vitamin B 12 started within the 'normal' range (Henning et al, 2001). The prevalence of deficient serum vitamin B 12 (12%) in older New Zealanders is higher than that reported in the United States in people Z60 y (B5%) (Wright et al, 1998) but lower than that reported in the United Kingdom in people aged 465 y (20%) (Bates et al, 2003). The reasons for the differing rates of deficient serum vitamin B 12 concentrations among these countries are unclear because median dietary intakes of vitamin B 12 are similar.…”

“…Estimates of the prevalence of low serum vitamin B 12 concentrations (o150 pmol/l) in older people range from 3 to 6% in the United States and 20% in the United Kingdom (Wright et al, 1998;Bates et al, 2003). In most cases, low serum vitamin B 12 concentrations in older people are not accompanied by megaloblastic anaemia.…”

Plenary Lecture 3 Food and the planet: nutritional dilemmas of greenhouse gas emission reductions through reduced intakes of meat and dairy foods

“…Furthermore, functional measures of status such as plasma or urinary methylmalonic acid, holotranscobalamin and homocysteine (tHcy) indicate a more widespread vitamin B 12 deficiency. Thus, a more detailed analysis of UK elderly subjects within NDNS has indicated that 46% of institutionalised elderly have elevated methylmalonic acid (106) . Importantly, several UK population studies of the elderly in the community have identified similar frequencies of elevated methylmalonic acid and have shown that low vitamin B 12 status, as indicated by elevated methylmalonic acid, low holotranscobalamin or elevated tHcys, is associated with cognitive decline (107)(108)(109) .…”

Folate and vitamin B12: friendly or enemy nutrients for the elderly

“…Estimates among the elderly vary widely; from 5% (based upon a low serum vitamin B 12 concentration) among institutionalized elderly adults in Germany, The Netherlands and Belgium (32) to 46% (based on multiple criteria including serum vitamin B 12 and methylmalonic acid (MMA)) among institutionalized elderly adults in the UK (33) . The impact on estimates of prevalence of using different criteria of deficiency can be illustrated by adapting data presented for a UK cohort of elderly adults (34) .…”