Increases in Plasma Holotranscobalamin Can Be Used to Assess Vitamin B-12 Absorption in Individuals with Low Plasma Vitamin B-12
| Autor: | Chittaranjan S. Yajnik, S. S. Naik, C. V. Joglekar, Nileema V. Thuse, Helga Refsum, Dattatray S. Bhat, Himangi Lubree, Caroline H.D. Fall, Carole Johnston, Lalita V Ramdas |
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| Rok vydání: | 2009 |
| Předmět: |
Vitamin
Vitamin b medicine.medical_specialty education.field_of_study Nutrition and Dietetics Malabsorption Chemistry Population Medicine (miscellaneous) Absorption (skin) medicine.disease Dietary vitamin chemistry.chemical_compound Endocrinology Internal medicine medicine Oral vitamin Cyanocobalamin education |
| Zdroj: | The Journal of Nutrition. 139:2119-2123 |
| ISSN: | 0022-3166 |
| DOI: | 10.3945/jn.109.107359 |
| Popis: | Low plasma concentrations of vitamin B-12 are common in Indians, possibly due to low dietary intakes of animal-source foods. Whether malabsorption of the vitamin contributes to this has not been investigated. A rise in the plasma holotranscobalamin (holo-TC) concentration after a standard dose of oral vitamin B-12 has been proposed as a measure of gastrointestinal absorption in people with normal plasma vitamin B-12 concentrations. We studied 313 individuals (children and parents, 109 families) in the Pune Maternal Nutrition Study. They received 3 doses of 10 microg (n = 191) or 2 microg (n = 122) of cyanocobalamin at 6-h intervals. A rise in plasma holo-TC of > or =15% and >15 pmol/L above baseline was considered normal vitamin B-12 absorption. The baseline plasma vitamin B-12 concentration was 10 micromol/L in children and >15 micromol/L in adults). In the 10 microg group, the plasma holo-TC concentration increased by 4.8-fold from (mean +/- SD) 9.3 +/- 7.0 pmol/L to 53.8 +/- 25.9 pmol/L and in the 2 microg group by 2.2-fold from 11.1 +/- 8.5 pmol/L to 35.7 +/- 19.3 pmol/L. Only 10% of the participants, mostly fathers, had an increase less than the suggested cut-points. Our results suggest that an increase in plasma holo-TC may be used to assess vitamin B-12 absorption in individuals with low vitamin B-12 status. Because malabsorption is unlikely to be a major reason for the low plasma vitamin B-12 concentrations in this population, increasing dietary vitamin B-12 should improve their status. |
| Databáze: | OpenAIRE |
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