Building healthy bones throughout life: an evidence-informed strategy to prevent osteoporosis in Australia

Osteoporosis imposes a tremendous burden on Australia: 1.2 million Australians have osteoporosis and 6.3 million have osteopenia. In the 2007–08 financial year, 82 000 Australians suffered fragility fractures, of which > 17 000 were hip fractures. In the 2000–01 financial year, direct costs were estimated at $1.9 billion per year and an additional $5.6 billion on indirect costs. Osteoporosis was designated a National Health Priority Area in 2002; however, implementation of national plans has not yet matched the rhetoric in terms of urgency. Building healthy bones throughout life, the Osteoporosis Australia strategy to prevent osteoporosis throughout the life cycle, presents an evidence-informed set of recommendations for consumers, health care professionals and policymakers. The strategy was adopted by consensus at the Osteoporosis Australia Summit in Sydney, 20 October 2011. Primary objectives throughout the life cycle are: to maximise peak bone mass during childhood and adolescence to prevent premature bone loss and improve or maintain muscle mass, strength and functional capacity in healthy adults to prevent and treat osteoporosis in order to minimise the risk of suffering fragility fractures, and reduce falls risk, in older people. The recommendations focus on three affordable and important interventions — to ensure people have adequate calcium intake, vitamin D levels and appropriate physical activity throughout their lives. Recommendations relevant to all stages of life include: daily dietary calcium intakes should be consistent with Australian and New Zealand guidelines serum levels of vitamin D in the general population should be above 50nmol/L in winter or early spring for optimal bone health regular weight-bearing physical activity, muscle strengthening exercises and challenging balance/mobility activities should be conducted in a safe environment.

Effects of maternal serum 25-hydroxyvitamin D concentrations in the first trimester on subsequent pregnancy outcomes in an Australian population

BACKGROUND

Low serum 25-hydroxyvitamin D [25(OH)D] concentrations during pregnancy have been associated with adverse pregnancy outcomes in a few studies but not in other studies.

OBJECTIVES

We assessed the serum 25(OH)D concentration at 10-14 wk of pregnancy and its association with adverse pregnancy outcomes and examined the predictive accuracy.

DESIGN

In this nested case-control study, we measured serum 25(OH)D in 5109 women with singleton pregnancies who were attending first-trimester screening in New South Wales, Australia. Multivariate logistic regression was conducted to examine the association between low 25(OH)D concentrations and adverse pregnancy outcomes (small for gestational age, preterm birth, preeclampsia, gestational diabetes, miscarriage, and stillbirth). The predictive accuracy of models was assessed.

RESULTS

The median (IQR) 25(OH)D concentration for the total population was 56.4 nmol/L (43.3-69.8 nmol/L). Serum 25(OH)D concentrations showed significant variation by parity, smoking, weight, season of sampling, country of birth, and socioeconomic status. After adjustment for maternal and clinical risk factors, low 25(OH)D concentrations were not associated with most adverse pregnancy outcomes. The area under the receiver operating characteristic curve (AUC) and likelihood ratio for a composite of severe adverse pregnancy outcomes of 25(OH)D concentrations <25 nmol/L were 0.51 and 1.44, respectively, and, for risk factors alone, were 0.64 and 2.87, respectively. The addition of 25(OH)D information to maternal and clinical risk factors did not improve the ability to predict severe adverse pregnancy outcomes (AUC: 0.64; likelihood ratio: 2.32; P = 0.39).

CONCLUSION

Low 25(OH)D serum concentrations in the first trimester of pregnancy are not associated with adverse pregnancy outcomes and do not predict complications any better than routinely assessed clinical and maternal risk-factor information.

Prospective audit of vitamin D levels of women presenting for their first antenatal visit at a tertiary centre

BACKGROUND

Vitamin D deficiency in pregnancy is associated with adverse events such as pre-eclampsia, primary caesarean section and vitamin D deficiency of the newborn. Vitamin D screening in pregnancy is not universal.

AIMS

To evaluate the vitamin D status of pregnant women at our institution and assess the sensitivity of the current risk-based screening guideline.

METHODS

A prospective audit of vitamin D levels of all women presenting for their first antenatal booking visit during 3 four-week periods (in 2009-2010) was conducted at the Women's and Children's Hospital, South Australia. The main outcome measure was 25-hydroxyvitamin D3 levels. Information was also collected on body mass index, self-reported ethnicity and whether or not vitamin D testing was indicated based on the hospital guidelines.

RESULTS

Four hundred and seventy-two women consented to inclusion in the audit. 67.4% (318/472) were 'low-risk' according to the hospital guidelines for vitamin D screening. 46.2% of these women and 78.6% of 'high-risk' women were vitamin D deficient (<60 nmol/L). Mean vitamin D levels were 62.7 ± 22.0 and 43.4 ± 26.3 nmol/L for low- and high-risk women, respectively. 54.9% (147/268) of women who were found to be vitamin D deficient were classified as 'low-risk' giving a sensitivity of 45% for the current risk-based screening guideline.

CONCLUSIONS

Based on current normal ranges for vitamin D, risk-based screening criteria for vitamin D deficiency in pregnancy fails to detect over half of vitamin D deficient women at our institution. Current South Australian guidelines should be amended in favour of universal screening of vitamin D for all pregnant patients at their booking visit.

Vitamin D levels in pregnant women booking for antenatal care in Far North Queensland

Serum concentrations of vitamin D were measured in pregnant women booking for antenatal care in Cairns Base Hospital, Queensland. Of 116 women, none was found to be vitamin D deficient. With a threshold of 50 nmol/L, no woman demonstrated vitamin D insufficiency; with a threshold of 75 nmol/L, 6.9% would have mild insufficiency. Further investigation into vitamin D concentrations of women living in northern Australia is required before recommendations are made for universal vitamin D screening of all pregnant women in Australia.