Is there a role for vitamin C in preventing osteoporosis and fractures?:A review of the potential underlying mechanisms and current epidemiological evidence

Osteoporosis and related fractures are a major global health issue, but there are few preventative strategies. Previously reported associations between higher intakes of fruits and vegetables and skeletal health have been suggested to be partly attributable to vitamin C. To date, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention but an overall consensus of published studies has not yet been drawn. The present review aims to provide a summary of the proposed underlying mechanisms of vitamin C on bone and reviews the current evidence in the literature, examining a potential link between vitamin C intake and status with osteoporosis and fractures. The Bradford Hill criteria were used to assess reported associations. Recent animal studies have provided insights into the involvement of vitamin C in osteoclastogenesis and osteoblastogenesis, and its role as a mediator of bone matrix deposition, affecting both the quantity and quality of bone collagen. Observational studies have provided some evidence for this in the general population, showing positive associations between dietary vitamin C intake and supplements and higher bone mineral density or reduced fracture risk. However, previous intervention studies were not sufficiently well designed to evaluate these associations. Epidemiological data are particularly limited for vitamin C status and for fracture risk and good-quality randomised controlled trials are needed to confirm previous epidemiological findings. The present review also highlights that associations between vitamin C and bone health may be non-linear and further research is needed to ascertain optimal intakes for osteoporosis and fracture prevention

Nitrogen, Phosphorus, and Suspended Solids Concentrations in Tributaries to the Great Bay Estuary Watershed in 2010

Nitrogen, phosphorus, and sediment loads to the Great Bay Estuary are a growing concern. The Piscataqua Region Estuaries Partnership (PREP) calculates the nitrogen load from tributaries to the Great Bay Estuary for its State of the Estuaries reports. Therefore, the purpose of this study was to collect representative data on nitrogen, phosphorus, and suspended sediment concentrations in tributaries to the Great Bay Estuary in 2010. The study design followed the tributary sampling design which was implemented by the New Hampshire Department of Environmental Services between 2001 and 2007 and by the University of New Hampshire in 2008 and 2009, so as to provide comparable data to the previous loading estimates

Nitrogen, Phosphorus, and Suspended Solids Concentrations in Tributaries to the Great Bay Estuary Watershed in 2011

Nitrogen, phosphorus, and sediment loads to the Great Bay Estuary are a growing concern. The Piscataqua Region Estuaries Partnership (PREP) calculates the nitrogen load from tributaries to the Great Bay Estuary for its State of the Estuaries reports. Therefore, the purpose of this study was to collect representative data on nitrogen, phosphorus, and suspended sediment concentrations in tributaries to the Great Bay Estuary in 2011. The study design followed the tributary sampling design which was implemented by the New Hampshire Department of Environmental Services between 2001 and 2007 and by the University of New Hampshire in 2008 and 2010, so as to provide comparable data to the previous loading estimates

Advection Dominated Accretion Flows Around Kerr Black Holes

We derive all relevant equations needed for constructing a global general relativistic model of advectively cooled, very hot, optically thin accretion disks around black holes and present solutions which describe advection dominated flows in the gravitational field of a Kerr black hole.Comment: ApJ submitte