Young adulthood is an important stage in the accrual of bone mass. Young women are often unaware of the need, and how to optimize modifiable risk factors, particularly intake of nutrients associated with good bone health. In this study, an accessible way to estimate osteoporosis risk, quantitative ultrasound (QUS), is compared to the gold-standard technique dual X-ray absorptiometry (DXA) in a group of 54 healthy young women (18–26 years) from Manawatu, New Zealand, and the relationship with nutrient intake is investigated. Broadband ultrasound attenuation and speed of sound (BUA, SOS) were assessed by QUS calcaneal scans and bone mineral concentration/density (BMC/BMD) were determined by DXA scans of the lumbar spine and hip (total and femoral neck). Dietary intake of energy, protein, and calcium was estimated using three-day food diaries and questionnaires. DXA mean Z-scores (>−2.0) for the hip (0.19) and spine (0.2) and QUS mean Z-scores (>−1.0) (0.41) were within the expected ranges. DXA (BMD) and QUS (BUA, SOS) measurements were strongly correlated. Median intakes of protein and calcium were 83.7 g/day and 784 mg/day, respectively. Protein intake was adequate and, whilst median calcium intake was higher than national average, it was below the Estimated Average Requirement (EAR). No significant relationship was found between dietary intake of calcium or protein and BMD or BMC. To conclude, QUS may provide a reasonable indicator of osteoporosis risk in young women but may not be an appropriate diagnostic tool. Increased calcium intake is recommended for this group, regardless of BMD.

The authors would like to make the following correction to our recent publication [1]. In the methods section (Section 2.6. Statistical Analysis), on page 3, the calculation of the sample size should read as follows:This study is a subset of a larger observational study. Initially, we determined the sample size for a correlation between DXA and QUS [2] using a type 1 error rate at 5% and type 2 error at 80% with an expected correlation coefficient of at least 0.5 (a moderate effect size), which has been found in other studies. This suggested a sample size of 29 participants. However, we wanted to ensure that we had a representative population including those with low bone mineral density [3]. Thus, the sample size was based on the predicted population of 18-25-year-old females (267,100 in New Zealand in 2013) [4] with an estimated 10% of women of that age having low bone mineral density (10% variability). Assuming a 95% confidence level and 10% precision (margin of error), the minimum sample size needed was 35 women. Factoring in for incomplete data sets/drop-outs between visits of 30%, a sample size of 50 women was required to ensure that 10% were classified as having low bone mineral density.The authors would like to apologize for any inconvenience caused by this amendment. This amendment does not affect the results or conclusion of the manuscript in any way. References 1. Schraders, K.; Zatta, G.; Kruger, M.; Coad, J.; Weber, J.; Brough, L.; Thomson, J. Quantitative Ultrasound and

Background: Critical determinants of bone health are genetics, diet and physical activity.Women face challenges to the modifiable risk factors [...]

We would like to thank Moran and Sanchez Fernandez [...]