Suboptimal vitamin D status among the South Asian UK population is widely reported; however, its impact on bone health is unclear. The aim of the present study was to conduct a comparative investigation of vitamin D status in postmenopausal South Asian (SA) and Caucasian (C) women and its relationship to parathyroid hormone (PTH) concentration, biochemical markers of bone turnover and bone quality. A cross-sectional study of community-dwelling women aged 50 -66 years was carried out. A total of sixty-six SA women of Pakistani origin and forty-two C women living in the same community were recruited. Fasting blood was taken for the measurement of vitamin D, PTH and biochemical markers of bone turnover, including type-1 collagen b C-telopeptide (bCTX), procollagen type-1 amino-terminal propeptide (P1NP), and bone-specific alkaline phosphatase (BAP) activity. Bone quality was assessed using broadband ultrasound attenuation (BUA). Total serum 25-hydroxyvitamin D (25(OH)D) was significantly lower in the SA women than the C women (medians: SA 10·5 v. C 47·1 nmol/l; P,0·001) This was associated with a significantly elevated serum PTH concentration in the SA group (medians: SA 7·3 v. C 4·5 pmol/l; P, 0·01). BAP activity was also significantly higher in the SA group, indicating elevated osteoblast activity and bone turnover (medians: SA 23·0 v. C 20·0 U/l; P,0·05). No significant differences were observed between the two groups for P1NP, bCTX or BUA. Although the SA women had significantly higher serum PTH and lower 25(OH)D concentrations than C women, this was not associated with significantly higher markers of bone resorption, or reduced bone quality in the SA women. Vitamin D: Bone turnover: South Asian womenSuboptimal vitamin D status among the South Asian UK population has been recognised for over 40 years, and is widely reported (1 -4) . Vitamin D deficiency impairs Ca and P absorption, resulting in poor mineralisation of the skeleton (5) , and is frequently associated with secondary hyperparathyroidism (1,6) ; therefore the impact of vitamin D deficiency on bone health is of concern, particularly among the elderly (3) . There is a lack of data regarding bone health and fracture risk in European minority ethnic populations, particularly those from the Indian subcontinent. As part of the recent Oslo Health Study, vitamin D status and biochemical markers of bone turnover were measured in Pakistanis aged 40 -60 years living in Oslo and compared with those of the local age-matched Norwegian population. Data from this study revealed that despite a high prevalence of vitamin D deficiency and secondary hyperparathyroidism in the Pakistani group, there was no difference in bone mineral density (BMD) measured at the forearm and there were only minor differences in bone turnover markers compared with the local Norwegian population (7) . The authors speculated that altered vitamin D metabolism in the Pakistani population protected their skeleton from bone loss. In contrast, studies of vitamin D status and bone mass in young...

1. Changes in the activities of several enzymes involved in mitochondrial fatty acid oxidation were measured in the livers of developing rats between late foetal life and maturity. The enzymes studied are medium-and long-chain ATP-dependent acyl-CoA synthetases of the outer mitochondrial membrane and matrix, GTP-dependent acyl-CoA synthetase, camitine acyltransferase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, general 3-oxoacyl-CoA thiolase and acetoacetyl-CoA thiolase. Developmental changes in the activity of cytoplasmic acetoacetyl-CoA thiolase were also investigated. 2. The activities of all the mitochondrial enzymes studied increase markedly at birth and, except for enoyl-CoA hydratase, decrease at weaning. However, all the developmental patterns other than those of enoyl-CoA hydratase and acetoacetyl-CoA thiolase exhibit a fall followed by a rise in enzyme activity during the mid-suckling period. 3. The cytoplasmic acetoacetyl-CoA thiolase activity is low throughout suckling, but high before birth and after weaning. 4. The results are discussed in relation to changes in fatty acid supply to the liver and hormonal changes occurring during development.

The following have been measured during the development of the laboratory rat: the rate of oxidation of palmitoylcarnitine, decanoylcarnitine, and 14C-palmitate by liver mitochondria; the concentrations of ketone bodies in the blood; the plasma concentrations of non-esterified fatty acids, glycerol, and triglyceride. In each case, a rise after birth and a fall at weaning were observed. These changes can be correlated with the dietary changes which occur at these times. However, during the suckling period, when a constant high fat content diet is consumed, further marked changes in the parameters measured were observed which cannot be related to nutritional factors.

The activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) has been determined in corpus callosum, subcortical white matter, and spinal cord of infants whose death was attributed to the sudden infant death syndrome (SIDS), and compared with enzyme activity in other cases in which the cause of death was not associated with respiratory distress. In nearly half the SIDS cases, CNPase activity and oligodendroglial cell numbers were reduced before the onset of myelination, but only in the corpus callosum. In other SIDS cases, enzyme activity and cell numbers were the same as in non-SIDS cases. If the expression of CNPase activity reflects glioblast differentiation to oligodendrocytes with myelinating potential, then this transformation is abnormal in certain SIDS cases, as also evidenced in cases of prolonged neonatal respiratory insufficiency and gives rise to a subsequent deficit of myelin in the corpus callosum.

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