~50% OF ELDERLY MALABSORB FOOD VITAMIN B12, DIAGNOSED BY LOW SERUM HOLOTRANSCOBALAM1N II......

CV# 796A. Flynn MA, Herbert V, Nolph GA, Krause G. ~50% of elderly have low serum holotranscobalamin II (B₁₂-TC), diagnosing vitamin B₁₂ malabsorption. 60% of this 50% also have high serum homocysteine; all with red cell folate >136 ng/ml. Giving elderly 25-100 micrograms oral free crystalline B₁₂ daily will save billions of dollars. FASEB J 1998;12: (4: PART I) : A246, Abstract #1435.

~50% OF ELDERLY MALABSORB FOOD VITAMIN B12, DIAGNOSED BY LOW SERUM HOLOTRANSCOBALAM1N II, OF WHOM 60% HAVE HIGH SERUM HOMOCYSTEINE; ALL HAVE RED CELL FOLATE >136 NG/ML. ELDERLY SHOULD ALL GET 25-100 µG ORAL FREE CRYSTALLINE B₁₂ DAILY. V Herbert, MA Flynn. GA Nolph, G Krause. Mount Sinai\Bronx VA Med Ctrs., New York, NY 10468 & U Missouri-Columbia, Columbia, MO 65212.

Of total serum B₁₂, ~20% is on delivery protein transcobalamin II (TC; half-life=6 min), and ~80% is on circulating storage protein haptocorrin (half-life=2 weeks). Every nucleated cell has TC receptors; only storage cells have receptors for haptocomn (Herbert V. In: Present Knowledge in Nutrition. (Eds: EE Ziegler & LJ Filer), Washington, DC, ILSI Press, 1996:191-205). Holo IC II is an ideal surrogate Schilling test (Ibid.) because it is low within a week of the start of B₁₂ malabsorption. Low serum holoTC II (and subtle neuropsychiatric and blood damage) may precede by many months high serum homocysteine (Hcy), methylmalonate, and low total B₁₂ (Ibid.). We (Flynn et al., J Am Coll Nutr 1997; 16:258-267) found, of 171 healthy elderly (mean age 65), 52 had Hcy>7.5 nmol/ml. These had serum holoTC 11<60 pg/ml, but only 7 had total B₁₂<200 pg/ml. An additional 31 of the 171 had holoTC<60 pg/ml, but still had enough stores to not yet have high Hcy. All 171 had red cell folate>136 ng/ml and serum folate >1.6 ng/ml, with the expected inverse relationship between Hcy and red cell (and serum) folate. We had earlier shown (Proc Soc Exp Biol Med 1958;99:257-259) 1% of oral crystalline B₁₂ is absorbed by mass action in gastric atrophy, and so now petitioned our government (Am Clin Nutr 1997;65:572-3) to mandate a minimum of 25 µg B₁₂ be added to all folate-fortified foods, and all folate supplements.