Matching articles for "Vitamin B12"
In Brief: Vitamin B12 Nasal Spray
The Medical Letter on Drugs and Therapeutics • August 1, 2005; (Issue 1214)
A nasal spray formulation of cyanocobalamin (Nascobal – Questcor) has been approved by the FDA for maintenance treatment of vitamin B12 deficiency. Nascobal is already available as an intranasal gel. Vitamin...
A nasal spray formulation of cyanocobalamin (Nascobal – Questcor) has been approved by the FDA for maintenance treatment of vitamin B12 deficiency. Nascobal is already available as an intranasal gel. Vitamin B12 deficiency, diagnosed by elevated serum concentrations of methylmalonic acid with or without elevated serum homocysteine and low serum B12 concentrations (<200 pg/mL), is common in older patients.1
Since intestinal absorption of B12 may be impaired, the usual maintenance treatment of deficiency is intramuscular injection of the vitamin in doses of 1 mg every 4 weeks (after more frequent doses have restored serum concentrations to normal levels). However, in patients with atrophic gastritis and even in those with pernicious anemia, some oral cyanocobalamin (about 1%) is absorbed by diffusion.2 A randomized, controlled trial comparing oral to parenteral cyanocobalamin therapy in deficient patients found daily oral 2-mg doses of the vitamin as effective as monthly injections.3
No studies have been reported with the expensive new formulation. Medical surveillance is recommended, no matter what treatment is used, to document normalization of hematologic indices.
1. R Clarke et al. Prevention of vitamin B-12 deficiency in old age. Am J Clin Nutr 2001; 73:151.
Since intestinal absorption of B12 may be impaired, the usual maintenance treatment of deficiency is intramuscular injection of the vitamin in doses of 1 mg every 4 weeks (after more frequent doses have restored serum concentrations to normal levels). However, in patients with atrophic gastritis and even in those with pernicious anemia, some oral cyanocobalamin (about 1%) is absorbed by diffusion.2 A randomized, controlled trial comparing oral to parenteral cyanocobalamin therapy in deficient patients found daily oral 2-mg doses of the vitamin as effective as monthly injections.3
No studies have been reported with the expensive new formulation. Medical surveillance is recommended, no matter what treatment is used, to document normalization of hematologic indices.
1. R Clarke et al. Prevention of vitamin B-12 deficiency in old age. Am J Clin Nutr 2001; 73:151.
2. FA Lederle. Oral cobalamin for pernicious anemia. Medicine’s best kept secret? JAMA 1991; 265:94.
Vitamin Supplements
The Medical Letter on Drugs and Therapeutics • July 18, 2005; (Issue 1213)
Many patients ask their physicians whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamin...
Many patients ask their physicians whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamin supplements.
Lowering Plasma Homocysteine
The Medical Letter on Drugs and Therapeutics • October 27, 2003; (Issue 1168)
High plasma homocysteine concentrations, like high cholesterol, have been associated with an increased risk of cardiovascular disease and death (O Nygσrd et al, N Engl J Med 1997; 337:230; RS Vasan et al, JAMA...
High plasma homocysteine concentrations, like high cholesterol, have been associated with an increased risk of cardiovascular disease and death (O Nygσrd et al, N Engl J Med 1997; 337:230; RS Vasan et al, JAMA 2003; 289:1251). In one meta-analysis, 25% lower plasma homocysteine concentrations were associated with 11% less coronary heart disease and 19% less stroke (Homocysteine Studies Collaboration, JAMA 2002; 288:2015). Should we be trying to lower serum homocysteine concentrations in our patients?