Vitamin D deficiency in UK South Asian Women of childbearing age: a comparative longitudinal investigation with UK Caucasian women

An estimate of the economic burden of vitamin D deficiency in pregnant women in the United Kingdom

Pregnancy is associated with an increased risk of vitamin D deficiency beyond that of the general population. The aim of the current analysis was to synthesize the current evidence on the dose-outcome relationship of vitamin D/serum 25 hydroxyvitamin D (25-OHD) and complications during pregnancy. An additional aim was to estimate the economic burden attributable to inadequate levels of serum 25-OHD. Published literature on the effects of vitamin D supplementation/serum 25-OHD on pregnancy complications, including randomized control trials and non-interventional studies, was searched in bibliographic databases including Pubmed, Google Scholar, Scopus and EMBASE. A positive and significant treatment effect was obtained for pre-eclampsia (OR = 0.75 95% CI 0.662-0.843), but not for preterm birth (OR = 0.783, 95% CI 0.49-1.251) or small for gestational age (OR = 0.76 95% CI 0.38-1.28). Inadequate vitamin D accounted for 14.04% of risk for pre-eclampsia. It is estimated that addressing vitamin D inadequacy in pregnant women in England and Wales would reduce the number of cases of pre-eclampsia by 4126; and would result in a net saving of £18.6 million for the NHS in England and Wales. The current results suggest that based on current evidence a public health policy preventing vitamin D inadequacy in pregnant women is likely to have a positive impact on the NHS budget in England and Wales. This is contingent upon further evidence regarding the vitamin D dose-pregnancy outcome relationship becoming available.

Maternal and neonatal vitamin-D status in twin versus singleton pregnancies

AIM

There is a paucity of information on vitamin D status of women with twin pregnancy and their newborns. This case-control study compared maternal and neonatal vitamin-D status in twin versus singleton pregnancies.

METHODS

Subjects included 50 women with twin pregnancy delivering at >28 weeks and 50 gestational-age-matched women with singleton pregnancy delivering during the same period. Maternal and neonatal serum 25-hydroxy vitamin D [25(OH)D] was compared between the two groups using the independent Student's t-test on log values. Serum albumin-adjusted calcium, inorganic phosphate, and intact parathormone levels were also compared.

RESULTS

Maternal vitamin-D deficiency (VDD; serum 25(OH)D < 30 nmol/L) was present in 90% of twin and 88% of singleton pregnancies. The prevalence of neonatal VDD was 89% in twin and 74% in singleton pregnancies (P = 0.03). Maternal serum 25(OH)D was lower in the twin group as compared to the singleton group (14.3 ± 10.47 vs 18.5 ± 12.36 nmol/L; P = 0.02). Mean serum calcium, intact parathormone, and inorganic phosphate were comparable between the women in the two groups. Maternal and neonatal 25(OH)D showed positive correlation in the two groups (P < 0.001). Mean cord blood 25(OH)D was significantly lower in the twins than in singleton newborns (14.8 ± 12.63 vs 22.6 ± 16.68 nmol/L; P = 0.002). The difference persisted even after adjustment for birthweights and maternal serum 25(OH)D. Mean serum calcium was significantly lower in the twins.

CONCLUSION

Twin newborns and their mothers have higher VDD as compared to singleton newborns and their mothers in the VDD population.

Vitamin D Deficiency with High Intact PTH Levels is More Common in Younger than in Older Women: A Study of Women Aged 39-64 Years

Low serum 25-hydroxyvitamin D (25(OH)D) levels are implicated as a risk factor for hip and spine fractures. Studies of the relation between 25(OH)D levels and fractures have primarily involved elderly osteoporosis patients or patients with fractures; however, the serum 25(OH)D and parathyroid hormone (PTH) status in younger adult populations remains largely unknown. We evaluated serum 25(OH)D and intact PTH levels in 411 women aged 39-64 years who were not receiving medication for osteoporosis or other bone diseases. Serum 25(OH)D levels were positively correlated with age (P = 0.019), whereas intact PTH levels were inversely correlated with 25(OH)D levels (P < 0.001). Thus, low vitamin D levels with high intact PTH levels were more common in younger than in older women. Our data show that serum 25(OH)D insufficiency could be a more serious concern in the younger population than had been previously anticipated. Because serum 25(OH)D insufficiency is reportedly a risk factor for hip and spine fracture, the number of fracture patients could increase in the future, suggesting that we may need to correct the serum vitamin D/intact PTH status to prevent future osteoporosis.

Vitamin D: An overview of vitamin D status and intake in Europe

In recent years, there have been reports suggesting a high prevalence of low vitamin D intakes and vitamin D deficiency or inadequate vitamin D status in Europe. Coupled with growing concern about the health risks associated with low vitamin D status, this has resulted in increased interest in the topic of vitamin D from healthcare professionals, the media and the public. Adequate vitamin D status has a key role in skeletal health. Prevention of the well-described vitamin D deficiency disorders of rickets and osteomalacia are clearly important, but there may also be an implication of low vitamin D status in bone loss, muscle weakness and falls and fragility fractures in older people, and these are highly significant public health issues in terms of morbidity, quality of life and costs to health services in Europe. Although there is no agreement on optimal plasma levels of vitamin D, it is apparent that blood 25-hydroxyvitamin D [25(OH)D] levels are often below recommended ranges for the general population and are particularly low in some subgroups of the population, such as those in institutions or who are housebound and non-Western immigrants. Reported estimates of vitamin D status within different European countries show large variation. However, comparison of studies across Europe is limited by their use of different methodologies. The prevalence of vitamin D deficiency [often defined as plasma 25(OH)D <25 nmol/l] may be more common in populations with a higher proportion of at-risk groups, and/or that have low consumption of foods rich in vitamin D (naturally rich or fortified) and low use of vitamin D supplements. The definition of an adequate or optimal vitamin D status is key in determining recommendations for a vitamin D intake that will enable satisfactory status to be maintained all year round, including the winter months. In most European countries, there seems to be a shortfall in achieving current vitamin D recommendations. An exception is Finland, where dietary survey data indicate that recent national policies that include fortification and supplementation, coupled with a high habitual intake of oil-rich fish, have resulted in an increase in vitamin D intakes, but this may not be a suitable strategy for all European populations. The ongoing standardisation of measurements in vitamin D research will facilitate a stronger evidence base on which policies can be determined. These policies may include promotion of dietary recommendations, food fortification, vitamin D supplementation and judicious sun exposure, but should take into account national, cultural and dietary habits. For European nations with supplementation policies, it is important that relevant parties ensure satisfactory uptake of these particularly in the most vulnerable groups of the population.

Nutritional status as assessed by nutrient intakes and biomarkers among women of childbearing age--is the burden of nutrient inadequacies growing in America?

OBJECTIVE

Understanding nutrient intakes among women of childbearing age within the USA is important given the accumulating evidence that maternal body weight gain and nutrient intakes prior to pregnancy may influence the health and well-being of the offspring. The objective of the present study was to evaluate nutritional status in women of childbearing age and to ascertain the influence of ethnicity and income on nutrient intakes.

DESIGN

Nutritional status was assessed using data on nutrient intakes through foods and supplements from the National Health and Nutrition Examination Survey. Biomarker data from the Centers for Disease Control and Prevention were used to assess nutritional status for selected nutrients. Poverty-income ratio was used to assess family income.

SUBJECTS

White (n 1560), African-American (n 889) and Mexican-American (n 761) women aged 19-30 and 31-50 years were included.

SETTING

A nationally representative sample of non-pregnant women of childbearing age resident in the USA.

RESULTS

African-American women had the lowest intakes of fibre, folate, riboflavin, P, K, Ca and Mg. Women (31-50 years) with a poverty-income ratio of ≤ 1.85 had significantly lower intakes of almost all nutrients analysed. Irrespective of ethnicity and income, a significant percentage of women were not consuming the estimated recommended amounts (Estimated Average Requirement) of several key nutrients: vitamin A (~80%), vitamin D (~78%) and fibre (~92%). Nutrient biomarker data were generally reflective of nutrient intake patterns among the different ethnic groups.

CONCLUSIONS

Women of childbearing age in the USA are not meeting nutrient intake guidelines, with differences between ethnic groups and socio-economic strata. These factors should be considered when establishing nutrition science advocacy and policy.

The short-term impact of vitamin D-based hip fracture prevention in older adults in the United Kingdom

PURPOSE

Vitamin D is a relatively inexpensive drug yet an important hormone in terms of calcium and bone homeostasis. Treatment with vitamin D is associated with reduced fracture risk particularly in an elderly population. Therefore, we assessed the budgetary impact of routine prescription of 800 IU daily colecalciferol on hip fracture among older adults in the United Kingdom.

METHODS

Using meta-analysis findings for treatment effect and UK-estimates of incidence, we performed a health economic evaluation of treating the UK population aged 65 and over with 800 IU of vitamin D daily, assessing the impact upon hip fracture costs using incremental attributable costs and excess mortality for a range of age- gender-based treatment strategies.

RESULTS

Using only a 1-year horizon, considering only reduction in hip fracture, prescribing colecalciferol 800 IU daily to all adults aged 65 and over, could reduce the number of incident hip fractures from 65,400 to 45,700, saving almost 1,700 associated deaths, whilst saving the UK taxpayer £22 million.

CONCLUSIONS

As the UK government seeks to reduce public expenditure in all sectors, investment in prescribed prophylactic colecalciferol 800 IU therapy for adults aged 65 and over is likely to yield cost savings through reduction hip fracture alone in the first year.

Rickets

Rickets, historically referred to as "the English disease", is common worldwide. Absence of phosphate at the growth plate and mineralising bone surfaces due to inadequate vitamin D supply either from sunlight exposure or diet is the main cause. Inherited disorders causing hypophosphataemia have shown the intricacies of phosphate metabolism. Present advice about the provision of vitamin D to young infants needs to be clarified; the existing guidance is fragmentary and contradictory, and will not help to eradicate the disease.

Plasma levels of 25-hydroxyvitamin D3 and in vivo markers of cytochrome P450 3A activity in Swedes and Koreans: effects of a genetic polymorphism and oral contraceptives

In vitro studies have shown that vitamin D may induce several cytochrome P450 (CYP) enzymes in general and CYP3A4 in particular. The primary aim of this study was to investigate the relationship between plasma levels of 25-hydroxyvitamin D3 and suggested in vivo markers of CYP3A activity in healthy volunteers from Sweden and Korea. Plasma concentrations of 25-hydroxyvitamin D3 were analysed in samples from three previously performed studies, and the correlation between these levels and suggested in vivo markers of CYP3A activity was investigated by means of nonparametric correlation. In addition, we studied the modulating effects of three vitamin D receptor promoter polymorphisms on the association between 25-hydroxyvitamin D3 and CYP3A enzyme activity in Swedish subjects. The plasma levels of 25-hydroxyvitamin D3 were not significantly associated with CYP3A phenotypes in any of the three studies, but after accounting for the vitamin D receptor polymorphism rs4516035, there was a significant positive association between 25-hydroxyvitamin D3 and CYP3A activity (p = 0.004). Swedes (n = 65) had significantly higher 25-hydroxyvitamin D3 levels than Koreans (n = 67), 75 nM compared with 31 nM (p < 0.001). Swedish women taking oral contraceptives (OC) (n = 19) had somewhat higher plasma levels of 25-hydroxyvitamin D3 compared with Swedish women not taking oral contraceptives (n = 21), 89 and 72 nM, respectively (p = 0.02). In conclusion, our results suggest that the overall influence on the CYP3A activity by 25-hydroxyvitamin D3 is of marginal importance.

Greater seasonal cycling of 25-hydroxyvitamin D is associated with increased parathyroid hormone and bone resorption

SUMMARY

This analysis assessed whether seasonal change in 25-hydroxyvitamin D concentration was associated with bone resorption, as evidenced by serum parathyroid hormone and C-terminal telopeptide concentrations. The main finding was that increased seasonal fluctuation in 25-hydroxyvitamin D was associated with increased levels of parathyroid hormone and C-terminal telopeptide.

INTRODUCTION

It is established that adequate 25-hydroxyvitamin D (25(OH)D, vitamin D) concentration is required for healthy bone mineralisation. It is unknown whether seasonal fluctuations in 25(OH)D also impact on bone health. If large seasonal fluctuations in 25(OH)D were associated with increased bone resorption, this would suggest a detriment to bone health. Therefore, this analysis assessed whether there is an association between seasonal variation in 25(OH)D and bone resorption.

METHODS

The participants were (n = 279) Caucasian and (n = 88) South Asian women (mean (±SD); age 48.2 years (14.4)) who participated in the longitudinal Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England study (2006-2007). The main outcomes were serum 25(OH)D, serum parathyroid hormone (sPTH) and serum C-terminal telopeptide of collagen (sCTX), sampled once per season for each participant.

RESULTS

Non-linear mixed modelling showed the (amplitude/mesor) ratio for seasonal change in log 25(OH)D to be predictive of log sPTH (estimate = 0.057, 95 % CI (0.051, 0.063), p < 0.0001). Therefore, individuals with a higher seasonal change in log 25(OH)D, adjusted for overall log 25(OH)D concentration, showed increased levels of log sPTH. There was a corresponding significant ability to predict the range of seasonal change in log 25(OH)D through the level of sCTX. Here, the corresponding parameter statistics were estimate = 0.528, 95 % CI (0.418, 0.638) and p ≤ 0.0001.

CONCLUSIONS

These findings suggest a possible detriment to bone health via increased levels of sPTH and sCTX in individuals with a larger seasonal change in 25(OH)D concentration. Further larger cohort studies are required to further investigate these preliminary findings.

Differential effects of different vitamin D replacement strategies in patients with diabetes

BACKGROUND

The optimal treatment regimen for correcting vitamin D insufficiency in diabetic patients has not been established.

METHODS

Two hundred and forty four adult diabetic patients with vitamin D insufficiency were enrolled to receive: Ergocalciferol (D2) 50,000 IU daily over 10 days (500,000 IU) followed by Calcichew D3 (calcium carbonate/Cholecalciferol) BID (~24,000 IU cholecalciferol/month) (ECC) (n=53); Cholecalciferol (D3) 40,000 IU daily over 10 days (400,000 IU) followed by Calcichew D3 BID (~24,000 IU cholecalciferol/month) (CCC) (n=94) or Cholecalciferol 40,000 IU daily over 10 days (400,000 IU) followed by Cholecalciferol 40,000 IU monthly (CC) (n=97). The 25(OH)D, HbA1c, lipids, blood pressure and eGFR were assessed at baseline and after a mean follow up of 8.0±4.0 months.

RESULTS

Treatment increased 25(OH)D concentrations significantly in ECC (17.4±13.8 vs 29.9±9.6 ng/ml, P<0.0001), CCC (14.2±6.6 vs 30.9±13.1 ng/ml, p<0.0001) and CC (13.5±8.4 vs 33.9±14.4 ng/ml, P<0.0001). The relative increase in 25(OH)D was significantly lower with ECC compared to CC (+14.6±12.2 vs +20.6±15.0, P=0.01) and the majority of subjects in the ECC group (63%) remained vitamin D deficient (25(OH)D <30 ng/ml) compared to CCC (46%) and CC (36%) (P=0.0005).

CONCLUSION

This study demonstrates that relatively aggressive treatment regimens of both vitamin D2 and D3 increase 25(OH)D concentrations in diabetic patients, but the ability to raise 25(OH)D status to 'sufficient' levels is inadequate in a large proportion of individuals.

Vitamin D and bone health outcomes in older age

The aim of this review is to summarise the evidence linking vitamin D to bone health outcomes in older adults. A plethora of scientific evidence globally suggests that large proportions of people have vitamin D deficiency and are not meeting recommended intakes. Older adults are at particular risk of the consequences of vitamin D deficiency owing to a combination of physiological and behavioural factors. Epidemiological studies show that low vitamin D status is associated with a variety of negative skeletal consequences in older adults including osteomalacia, reduced bone mineral density, impaired Ca absorption and secondary hyperparathyroidism. There seems to be inconsistent evidence for a protective role of vitamin D supplementation alone on bone mass. However, it is generally accepted that vitamin D (17·5 μg/d) in combination with Ca (1200 mg/d) reduces bone loss among older white subjects. Evidence for a benefit of vitamin D supplementation alone on reducing fracture risk is varied. According to a recent Agency for Healthcare Research and Quality review in the USA the evidence base shows mixed results for a beneficial effect of vitamin D on decreasing overall fracture risk. Limitations such as poor compliance with treatment, incomplete assessment of vitamin D status and large drop-out rates however, have been highlighted within some studies. In conclusion, it is generally accepted that vitamin D in combination with Ca reduces the risk of non-vertebral fractures particularly those in institutional care. The lack of data on vitamin D and bone health outcomes in certain population groups such as diverse racial groups warrants attention.

Determinants of vitamin D status in long-term renal transplant patients

In this study, we explored the determinants of vitamin D status in a large cohort of stable, Long-term renal transplant (RTx) patients. Serum 25(OH)D concentrations, and bone biochemistry parameters, were retrospectively analyzed from 266 RTx patients (>10 yr post-engraftment) presenting to clinic over the course of a year. Forty-five percent of the cohort were vitamin D deficient (<37.5 nM), 38% insufficient (37.5 75-nM), and 17% sufficient (>75 nM). Serum 25(OH)D concentrations were higher in patients presenting in summer (p<0.001) and in more active patients (p<0.05). RTx patients with non-melanoma skin cancer (NMSC) (n=45) had higher 25(OH)D concentrations than patients without NMSC (n=221; p<0.05) despite these patients being older, having worse eGFR, transplanted for longer, and less active physically (p<0.05). Lower 25(OH)D concentrations were associated with higher PTH concentrations (p<0.05) which, in the setting of widespread hypovitaminosis, suggests that secondary hyperparathyroidism was common in this cohort. In conclusion, season and activity status are important determinants of vitamin D status. We report, for the first time, that NMSC is associated with higher 25(OH)D, probably through increased UV radiation exposure. Long-term RTx patients may benefit from oral vitamin D supplementation, but this requires a randomized controlled trial to confirm.