It is important to maintain adequate vitamin D levels all year round for bone health (Ministry of Health and Cancer Society of New Zealand 2012). Low levels have been associated with reduced bone mineral density, high bone turnover and increased risk of hip fracture (Nowson et al 2012). There is an association between lower serum vitamin D levels and falling (Annweiler and Beauchet 2015).
Most people don’t need vitamin D supplements, but some do
For those who are deficient in vitamin D and unable to increase their exposure to direct sunlight, supplements can be prescribed. One rationale for vitamin D supplementation is that vitamin D supplements may help prevent falls.
Vitamin D deficiency can be assumed for the following groups and a blood test is not necessary: those who are housebound, completely cover their skin or have very dark skin. Many residents of aged residential care facilities meet these criteria (bpacNZ 2011; bpacNZ 2016).
For practical purposes, people at risk of vitamin D deficiency are those that answer ‘yes’ to one or more of the following questions:
- Do you spend little time outside in the sun?
- When outside do you cover up for cultural, medical or other reasons?
- Do you have naturally very dark skin?
Vitamin D testing is only justified to address a specific diagnostic question.
New Zealand guidance for vitamin D supplementation
- bpacNZ has published New Zealand-specific guidance for clinicians on vitamin D supplementation.
- Most people can achieve adequate levels of vitamin D through exposure to sunlight.
- Only prescribe vitamin D supplementation for frail older people or those at risk of deficiency. Older residents in long-term care are more likely to meet these criteria.
- ACC, district health boards and primary health organisations support the provision of vitamin D supplements for older people who live in residential care facilities.
- Monthly vitamin D supplements must be prescribed but lower doses are available over the counter, eg, as cod liver oil tablets.
- In addition to doctors, health practitioners able to prescribe vitamin D include dieticians, pharmacists and nurse practitioners who have met the relevant regulatory requirements for prescribing.
- The standard treatment in New Zealand for people with vitamin D deficiency, and who are unable to increase exposure to sun, is one x 50,000 IU cholecalciferol tablet a month, with the option of an initial loading dose of one tablet a day for up to 10 days if the vitamin D deficiency is severe.
- Routine supplementation for the general population is not recommended as it does not reduce falls or fractures (Bolland et al 2015; Reid et al 2014).
- Testing vitamin D levels is rarely required. It is expensive and often unreliable (LeFevre 2015; CADTH 2015).
Recent resources supporting this guidance
Osteoporosis New Zealand recommends sunlight for vitamin D
Published guidance from Osteoporosis New Zealand recommends 5–10 minutes of sunlight exposure 4–6 times per week is sufficient to generate adequate vitamin D levels. Only those individuals at risk of vitamin D deficiency (frail/institutionalised elderly, veiled women and those with dark skin) should require supplementation.
The US Preventive Services Task Force recommends against vitamin D supplementation to prevent falls
The USPSTF 2017 draft recommendation statement recommends against vitamin D supplementation to prevent falls in community-dwelling adults age 65 years or older, having found adequate evidence that vitamin D supplementation has no benefit in preventing falls in older adults living in the community.
The ViDA study found that vitamin D does not prevent falls or fractures
The large, double-blind, placebo-controlled ViDA trial showed that high-dose bolus vitamin D supplementation of 100,000 IU colecalciferol monthly did not prevent falls or fractures in a healthy adult population (Khaw et al 2017). This is consistent with the 10 Topics advice to reserve vitamin D supplementation for those likely to be deficient in vitamin D (see Topic 4 and above).
A 2017 meta-analysis in JAMA found that vitamin D is not associated with a lower risk of fractures
A meta-analysis of randomised controlled trials published in the Journal of the American Medical Association (JAMA), found that calcium, vitamin D, or the two combined, are not associated with a lower risk of fractures among community-dwelling older adults (Zhao et al 2017).
Consumer information resources on prescribed vitamin D supplements have been developed jointly by ACC, the Health Quality & Safety Commission, the Ministry of Health and the Cancer Society.
These resources and promotional posters include:
- promotional posters for display in general practice, pharmacies and other settings
- a consumer information brochure suitable for printing (this has been widely distributed to general practices in hard copy as a MediBoard promotion through ACC)
- a consumer information sheet suitable for online reading.
Annweiler C, Beauchet O. 2015. Questioning vitamin D status of elderly fallers and nonfallers: a meta-analysis to address a 'forgotten step'. Journal of Internal Medicine 277(1): 16–44.
Bolland M, Grey A, Reid I. 2015. Should we prescribe calcium or vitamin D supplements to treat or prevent osteoporosis? Climacteric 18(sup2): 22–31.
bpacNZ. 2011. Vitamin D supplementation: Navigating the debate. Best Practice Journal 36: 26–35.
bpacNZ. 2016. Vitamin D and calcium supplementation in primary care: an update. Best Practice Journal 76: https://bpac.org.nz/BPJ/2016/July/supplementation.aspx.
CADTH. 2015. Vitamin D testing in the general population: a review of the clinical and cost-effectiveness and guidelines. Ottowa: Canadian Agency for Drugs and Technologies in Health. https://www.ncbi.nlm.nih.gov/books/NBK274106/.
Khaw KT, Stewart AW, Waayer D, et al. 2017. Effect of monthly high-dose vitamin D supplementation on falls and non-vertebral fractures: secondary and post-hoc outcomes from the randomised, double-blind, placebo-controlled ViDA trial. Lancet Diabetes Endocrinol 5(6): 438–47.
LeFevre ML, USPSTF. 2015. Screening for vitamin D deficiency in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 162(2): 133–40.
Ministry of Health and Cancer Society of New Zealand. 2012. Consensus Statement on Vitamin D and Sun Exposure in New Zealand. Wellington: Ministry of Health, ACC, Cancer Society of New Zealand.
Nowson CA, McGrath JJ, Ebeling PR, et al. 2012. Vitamin D and health in adults in Australia and New Zealand: a position statement. Medical Journal of Australia 196(11): 686–7.
Reid IR, Bolland MJ, Grey A. 2014. Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis. The Lancet 383(9912): 146–55.
Zhao JG, Zeng XT, Wang J, et al. 2017. Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis. JAMA 318(24): 2466–82.