Signs Of Vitamin B12 Deficiency Research Articles

Clinical Implications of Vitamin B12 Deficiency in the Elderly

Vitamin B12 deficiency is a prevalent condition in the elderly. Depending on the diagnostic criteria used, more than 10% to 15% of people over the age of 60 are estimated to be deficient in vitamin B12. Diagnosis can be problematic because vitamin B12 deficiency may present as neurological or mental-status changes—which can be confused with symptoms of other age-related neurological disorders—rather than as megaloblastic anemia. A higher folate intake, due to the fortification of flour with this B vitamin, can mask and/or precipitate the hematologic signs of vitamin B12 deficiency, potentially delaying diagnosis and treatment, and increasing the risk of irreversible neurological damage to elderly people with subtle vitamin B12 deficiency. This paper will discuss two conditions contributing to the high prevalence of vitamin B12 deficiency in the elderly, as well as approaches to its diagnosis and treatment.

Home parenteral nutrition and vitamin B12 status

The vitamin B12 status of 20 subjects who were on home parenteral nutrition after surgical or functional small bowel resection and were given 1000 micrograms cyanocobalamin every 3 mo was studied by comparing their plasma vitamin B12, homocysteine (HS), and methylmalonic acid (MMA) concentrations. The plasma vitamin B12 concentration (median 145 pmol/L, 95% confidence interval: 123-217) was subnormal in four cases and borderline in four others. In the "4low B12" group, the concentrations of the markers of vitamin B12 deficiency were in the normal range; HS 10.7 mumol/L (8.0-12.3); and MMA, 0.15 mumol/L (0.09-0.19). References values were HS, 10.0 mumol/L (9.4-12.6); and MMA, 0.16 mumol/L (0.10-0.19). Thus, there were no metabolic signs of vitamin B12 deficiency in these subjects on parenteral nutrition, despite the fact that their plasma vitamin B12 levels were low. Analysis of individual data showed that the four patients with low circulating B12 had markers of intracellular vitamin B12 deficiency in the normal range.

Vitamin B12 absorption and exocrine pancreatic insufficiency in childhood.

The absorption of vitamin B12, labelled with radioactive 58Co, was measured in 19 patients with cystic fibrosis and one child with the Shwachman-Diamond syndrome using the whole body counting technique. We found vitamin B12 absorption reduced to 7.97 on average, compared to 59.2% for the control group. The low vitamin B12 absorption correlated well with the reduced fat retention coefficients. After adding 0.212 pancreatin to the radioactive vitamin B12 test dose, the absorption quotas improved in all cases, the average being 61%. A meal poor in vitamin B12 tended to increase the absorption of the radioactive test dose to 23% on average. As yet there is no satisfactory explanation for the effect of the diet on the absorption of vitamin B12 in exocrine pancreatic insufficiency. This could be the reason why the malabsorption of vitamin B12 in patients with EPI can go unnoticed for many years and could possibly explain why vitamin B12 malabsorption in exocrine pancreatic insufficiency does not cause symptoms and signs of vitamin B12 deficiency for many years.

Metabolism of vitamin B12 and early signs of vitamin B12 deficiency in man.

Metabolism of vitamin B12 and early signs of vitamin B12 deficiency in man.

Hyperpigmentation of skin. A sign of vitamin-B12 deficiency.

Increase of melanin pigmentation in the skin is well known to occur in a variety of conditions. such as Addison's disease of the suprarenals, pregnancy, and various debilitating diseases. Pigmentation of the skin has also been described in tropical sprue (Bahr, 1915; Baker, 1957). In continuing the study of pigmentation in subjects with tropical sprue and tropical megaloblastic anaemia, we have come to recognize one type of pigmen tation as being associated specifically with vitamin-B12 deficiency. This paper describes some of these cases and the investigations undertaken to establish the aetiology of the pigmentation.