Iuliano-Burns, S and Ayton, J and Hillam, S and Jones, G and King, K and Macleod, S and Seeman, E, Skeletal and hormonal responses to vitamin D supplementation during sunlight deprivation in Antarctic expeditioners, Osteoporosis International, 23, (10) pp. 2461-2467. ISSN 1433-2965 (2012) [Refereed Article]
Copyright 2011 International Osteoporosis Foundation and National Osteoporosis Foundation
Introduction: Antarctic expeditioners are exposed to prolonged sunlight deprivation resulting in vitamin D deficiency. We hypothesised that monthly dosing of 50,000 IU vitamin D (~1,600 IU daily) will increase serum 25-hydroxyvitamin D (25(OH)D), suppress parathyroid hormone (PTH) and improve bone mineral density (BMD), 50,000 IU alternate months (~800 IU daily) will maintain these measures, while a single 50,000 IU dose pre-departure (~1,00 IU daily) will not be protective.
Methods: This was a randomised double-blind study involving 110 healthy adults: 91 males, mean age 41 years (range 24-65 years) working in Antarctica for up to 12 months, who we administered 50,000 IU vitamin D3 monthly, alternate months or a single dose pre-departure. Serum 25(OH)D, PTH, osteocalcin, CTx and calcium were assessed at baseline, mid- and end of expedition. Proximal femur and lumbar spine BMD were assessed pre- and post-expedition.
Results: Baseline 25(OH)D was 59 ± 14 nmol/L. By mid-expedition, 25(OH)D increased by 7 nmol/L in those supplemented monthly (p < 0.05) and remained unchanged in those supplemented in alternate months. In those given a single dose pre-departure, 25(OH)D decreased by 8 nmol/L (p < 0.05) and PTH increased by 27% (p < 0.09). Serum osteocalcin increased by ~22% in all groups but BMD remained unchanged. If serum 25(OH)D was >50 nmol/L at baseline, 25(OH)D was maintained above this level with all regimens. If 25(OH)D was <50 nmol/L at baseline, monthly or alternate month regimens were needed to achieve levels >50 nmol/L, the single pre-departure dose was ineffective.Conclusion: During sunlight deprivation of up to 12 months, serum 25(OH)D levels can be maintained above 50 nmol/L when expeditioners are provided with 50,000 I U at least every alternate month.
|Item Type:||Refereed Article|
|Keywords:||Antarctica, sunlight deprivation, Vitamin D supplementation|
|Research Division:||Biomedical and Clinical Sciences|
|Research Group:||Clinical sciences|
|Research Field:||Rheumatology and arthritis|
|Objective Group:||Clinical health|
|Objective Field:||Clinical health not elsewhere classified|
|UTAS Author:||Jones, G (Professor Graeme Jones)|
|Web of Science® Times Cited:||11|
|Deposited By:||Menzies Institute for Medical Research|
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