Safety and Effectiveness of Stoss Therapy in Children with Vitamin D Deficiency

Objectives: Paediatric vitamin D (25-hydroxyvitamin D - 25OHD) deficiency can lead to nutritional rickets and extra-skeletal complications. Compliance with daily therapy can be difficult, making high dose, short-term vitamin D (stoss) therapy attractive to correct vitamin D deficiency. We compared the effectiveness and safety of standard versus stoss therapy in treating childhood 25OHD deficiency. Study Design: Children aged 2 - 16 years with 25OHD \u3c50nmol/L were randomized to either standard (5,000IU daily for 80 days) or stoss (100,000 IU weekly for 4 weeks) cholecalciferol. Participants underwent evaluation of effectiveness and safety. 25OHD, random spot calcium: creatinine ratio (Ca:Cr) and compliance were measured at 12 weeks. Results: 151 children were enrolled in the study (68 standard and 83 stoss), median age 9 years (IQR: 6 - 12 years). Baseline 25OHD levels were 26 nmol/L (IQR: 19 - 35 nmol/L) and 32 nmol/L (IQR: 24 - 39 nmol/L) in the standard and stoss groups respectively. At 12 weeks, the median 25OHD level was significantly greater in the standard vs. stoss group (81 vs. 67 nmol/L; p=0.005), however, \u3e80% of participants in both groups achieved sufficiency (25OHD\u3e50nmol/L) and had normal urinary Ca:Cr, with no significant difference seen between groups. Compliance was similar in the two groups. Conclusion: Compared to stoss, standard therapy achieved higher 25OHD levels at 12 weeks; however, in both groups there were a similar proportion of participants who achieved 25OHD sufficiency, with no evidence of toxicity. Unlike other studies, simplifying the treatment regimen did not improve compliance. These results support stoss therapy as an effective and safe alternative therapy for the treatment of paediatric vitamin D deficiency

Avoiding Rotated Bitboards with Direct Lookup

This paper describes an approach for obtaining direct access to the attacked squares of sliding pieces without resorting to rotated bitboards. The technique involves creating four hash tables using the built in hash arrays from an interpreted, high level language. The rank, file, and diagonal occupancy are first isolated by masking the desired portion of the board. The attacked squares are then directly retrieved from the hash tables. Maintaining incrementally updated rotated bitboards becomes unnecessary as does all the updating, mapping and shifting required to access the attacked squares. Finally, rotated bitboard move generation speed is compared with that of the direct hash table lookup method.Comment: 7 pages, 1 figure, 4 listings; replaced test positions, fixed typo