Vitamin: B12, cobalamin.

RDA, Hazardous level. men 51+. 6 mcg none

women 51+ 6 mcg none

Average intake in US diet: 7.84 mcg

SENIOR DOSAGE RATIONALE:150% of USRDA is desirable, adjusted for weight and intake

KEY NOTES AND REFERENCES:

Herzlich, B.C., et al , “Relationship among homocyst(e)ine, vitamin B-12 and cardiac disease in the

elderly: association between vitamin B-12 deficiency and decreased left ventricular ejection fraction”, J

Nutr. 126: 1249S-53S (1996)

“We evaluated the association of moderate hyperhomocyst(e)inemia and vitamin B-12 status with coronary artery disease (CAD) and left ventricular ejection fraction in 367 elderly patients… In conclusion, vitamin B-12-deficient patients had significantly lower left ventricular ejection fractions than nonvitamin B-12-deficient patients.”

Koehler, K.M., et al, “Vitamin supplementation and other variables affecting serum homocysteine and

methylmalonic acid concentrations in elderly men and women, J Am Coll Nutr. 15: 364-76 (1996)

“An elevated serum concentration of the metabolite, homocysteine (Hcys): 1) can indicate folate or vitamin B12 deficiency, 2) is an independent risk factor for vascular disease. .. to determine the effect of self-selected vitamin supplementation and other variables … for elderly volunteers, age 68-96 years, and compared for those consuming (26 men, 25 women) and not consuming (24 men, 25 women) self-selected vitamin supplements. RESULTS: Compared with the nonsupplemented group, the supplemented group had lower mean serum MMA (208 +/- 162 vs. 241 +/- 98 nmol/L [+/- SD]) and Hcys (9.5 +/- 2.6 vs. 11.2 +/- 2.7 mumol/L); and higher serum vitamin B12 (391 +/- 174 vs 292 +/- 107 pmol/L), and serum folate (46 +/- 15 vs. 24 +/- 10 nmol/L) p < 0.05… Clinicians should be aware of the risk of vitamin B12 deficiency in older people… These elderly volunteers had generally good folate status; nevertheless, some subjects seemed likely to benefit from an improvement in folate status that would reduce their serum Hcys within the normal range.”

Piyathilake, C.J., et al, “Cigarette smoking, intracellular vitamin deficiency, and occurrence of micronuclei in epithelial cells of the buccal mucosa”, Cancer Epidemiol Biomarkers Prev. 4: 751-8 (1995) “The study focuses on the assessment of chromosomal damage associated with folate and vitamin B12 deficiency…. The presence of vitamin B12 in the immediate environment (saliva) and vitamin C and E in the plasma, however, appear to be marginally protective against chromosomal damage in buccal mucosal cells.”