SUMMARY. The concentrations of serum calcium, parathyroid hormone (PTH), 25 Hydroxyvitamin D (250HD), and 1,25 Dihydroxyvitamin D (1,25(OH}zD) were determined in 99 Saudi patients with sickle cell disease and in 104 matching healthy controls. Serum calcium and 250HD were significantly lower in the patients, with 140/0 and 12% of them had serum calcium and 250HD concentrations, respectively, below the normal range. PTH was significantly higher in the patients, with 31% having values above the normal range. There was no significant difference between patients and controls in regard to 1,25(OH}zD. There was a significant inverse correlation of 250HD with PTH and a direct correlation of PTH with 1,25(OH}zD. Dietary intake of calcium and vitamin D was adequate in both patients and controls. The results indicate that sickle cell patients have hypocalcaemic tendency associated with supranormal PTH, and imply impaired intestinal absorption of calcium and vitamin D leading to a disturbed calcium metabolism which might contribute to the skeletal changes seen in sickle cell disease.Additional key phrases: diet; sunlight; 25 cholecalciferol; 1,25 cholecalciferol Vitamin D synthesized in the skin and absorbed in the intestine, undergoes metabolic transformations before exerting its effect on target tissues

Calcium intake and physical activity level (PAL) were assessed by questionnaire in 124 healthy women aged 52-62 y to determine the effect of calcium intake and PAL on bone mass and turnover. Four groups were identified according to their different reported calcium intakes and PALs. Bone mineral density (BMD) at the spine, hip, and left os calcis was measured together with total bone mineral content (TBMC) with dual-energy X-ray absorptiometry. Bone formation and resorption biochemical markers were measured in fasting samples of blood and urine. Women with the highest calcium intakes and PALs had the highest BMD at all sites compared with those with the lowest calcium intakes and PALs (P < 0.001). Calcium intake and PAL were positively correlated with BMD at all sites. Bone turnover markers did not explain the variation in bone mass between groups. In stepwise-multiple-regression analysis only calcium intake, physical activity, age, or weight remained as independent predictors of BMD and TBMC. When subjects were divided by past PALs, calcium intake and PAL were second to age and weight in their influence on spinal and hip BMD, but remained influential on the os calcis and whole body. We conclude that current high calcium intakes and PALs influence BMD at the os calcis and TBMC and protect bone mass in women 5-12 y postmenopausal at all measured sites, including the spine and hip. This finding does not exclude the possibility of past influences of calcium and activity on bone mass.

The results provide a good representation of typical portion weights for different foods and food groups in primary and secondary schools in England. Portion size is one factor that determines nutrient intake. New standards for school lunches are both nutrient and food-based. Guidance on portion weights will help to ensure that pupils consume the correct balance of foods to obtain the recommended nutrient intake. The present findings complement and extend existing guidance on portion sizes for pupils in schools in England and Scotland.