Vitamin D deficiency

This section provides information and statistics on vitamin D deficiency in New Zealand.

Vitamin D deficiency can be caused by too little UV exposure, and can affect bone health. It can lead to:

  • rickets (bowed legs and knocked knees) in children
  • osteomalacia and osteoporosis (affecting the bones) in adults.

Sunlight is the main source of vitamin D, but we can also get small amounts in our diet.

On this page:

One in twenty adults have vitamin D deficiency
People more at risk in winter and in South Island

One in twenty adults have vitamin D deficiency

About 4.9 percent of New Zealand adults had vitamin D deficiency in 2008/09 [1]. This included 0.2 percent of adults with severe deficiency.  A further one in four adults (27.1 percent) were below recommended levels of vitamin D.

The following population groups had higher levels of vitamin D deficiency:

  • Pacific adults
  • people who lived in the most socioeconomically deprived areas (NZDep2006 quintile 5) 
  • people who were obese.

Men and women had similar levels of vitamin D deficiency. Rates were also similar across age groups.

People more at risk in winter and in South Island

Vitamin D deficiency is more common in late winter and early spring (August to October) in New Zealand.  This is because UV levels are lower during these months, and people are less likely to get exposure to the sun.

In particular, people living in the South Island were more at risk of vitamin D deficiency during late winter and spring.

Information about the data

Prevalence of Vitamin D deficiency
Source: Vitamin D Status of New Zealand Adults [1].  Data come from the 2008/09 New Zealand Adult Nutrition Survey. Vitamin D deficiency was based on blood samples collected as part of the survey. 
Definition: Proportion of the adult population (aged 15+ years) who have vitamin D deficiency. This is defined as a serum 25-OHD level less than 25.0 nmol/L. Severe deficiency was defined as a serum 25-OHD level less than 12.5 nmol/L.  The Ministry of Health recommends that individuals have an annual mean vitamin D (serum 25-OHD) level of 50.0 nmol/L or greater.

References

1. Ministry of Health. 2012. Vitamin D Status of New Zealand Adults: Findings from the 2008/09 New Zealand Adult Nutrition Survey.Wellington: Ministry of Health.