Optimization of daily folate, vitamin B12 and vitamin B6 supplements in paediatric patients with sickle cell disease

We determined optimal folate, vitamin B12 and vitamin B6 dosages in 21 sickle cell disease (SCD) patients (11 HbSS, 10 HbSC; mean 7 years, range 7-16), using plasma homocysteine (Hcy) as functional marker. They received daily 400 g (0-3 weeks), 700 g (3-6) and 1000 g (6-70) folate; 1 (0-21), 3 (21-45 and 5 RDA (45-70) vitamin B12; and 1 RDA vitamin B6 (0-70). Blood was taken at baseline (P0) and after 3 (PI), 6 (P2), 9 (P3), 21 (P4), 33 (P5), 45 (P6), 57 (P7) and 70 (P8) weeks for measurement of erythrocyte (RBC), serum folate, plasma vitamin B12, whole blood vitamin B6 and plasma Hcy. Vitamin B6 increased from P0 to P1 and P1 to P2; vitamin B12 from P4 to P8; serum folate from P0 to P1 and P1 to P2; RBC folate from P0 to P1, P1 to P2 and P2 to P3. Hcy decreased from P1 to P2 and P4 to P6. Most pronounced Hcy decreases occurred from P0 to P1 (43 percent of patients), P1 to P2 (14 percent) and P4 to P5 (24 percent). Haematological indices did not change. Patients with HbSS had higher RBC folate at P1, P2 and P8. The entire group exhibited inverse relations between RBC folate and haemoglobin on P1, P2, P3, P6, P7 and P8. We conclude that RBC folate is less valuable for folate status assessment in SCD patients. The optimal daily supplement is 700 g folate (3.5-7 RDA vitamin B12 (4.2-6.0 g) and 1 RDA vitamin B6 (1.4-2.0 mg). This combination causes Hcy levels that do not decrease further upon higher dosages and may reduce by simple and relatively inexpensive means their inherently high risk of endothelial damage.(Au)

Folic acid status of paediatric patients with sickle cell disease

We investigated whether paediatric patients with sickle cell disease (9ñ4 years; 27 HbSS; 19 HbSC) have different folic acid status compared with age-, sex-and race-matched HbAA controls (n=20), and whether their folic acid status can be improved by folic acid supplementation. The patients were supplemented with vitamins B6 and B12 during one week and with folic acid during the next week. Circulating folic acid, homocysteine, vitamin B6 and vitamin B12 levels were measured at baseline (patients and controls), after 1 and 2 weeks (patients). The patients had similar folic acid, vitamin B6 and vitamin B12, but higher homocysteine levels, compared with HbAA controls (12.7ñ4.5 vs 10.9ñ3.5 mmol/l;p=0.04). Vitamin B6 and B12 supplementation did not change their homocysteine levels, but folic acid supplementation caused a 52 percent reduction (to 5.7ñ1.6). We conclude that patients with sickle cell disease have adequate vitamin B6 and B12 status, but suboptimal folic acid status. They may benefit from folic acid supplementation to reduce their high risk for endothelial damage.(AU)