Getting your daily vitamin D Me pēhea e kai i tō huaora D o ia rā

Your body makes most of the vitamin D it needs in your skin when exposed to direct sunlight. Sunlight through glass does not work because the glass blocks out the ultraviolet B rays needed to make vitamin D.

You can get some vitamin D from foods, but this is not enough by itself.

Your body cannot store much vitamin D, so you need to keep topping it up.

Being low in vitamin D can lead to a loss of bone density which can contribute to thinner and weaker bones than normal (osteoporosis).

Osteoporosis

Being very low in vitamin D can cause muscle weakness and soft and painful bones (osteomalacia). In babies and children this condition is known as rickets.

Rickets — Vitamin D and your babyexternal link

Risk factors for being low in vitamin D include:

• spending little time outdoors due to work, illness, or age
• living in the South Island and spending little time outdoors
• having naturally very dark skin
• covering most of your skin when outdoors
• having to avoid sunlight because of other health conditions (such as skin cancer) or medications that you are taking
• having a medical condition that affects Vitamin D absorption such as coeliac disease or Crohn's disease.

Sensible sun exposure is the best way to get your vitamin D. Most people only need a short amount of time in the sun to make enough vitamin D.

The amount of sun exposure you can safely have depends on several factors such as:

• your skin colour
• if you are taking medications — some medications make your skin more sensitive to sunburn
• where you are in Aotearoa New Zealand, the season and the time of day
• certain medical conditions
• if you have previously had skin cancer.

General recommendations for Aotearoa New Zealand depend on the time of year.

September to April

A daily walk or some other form of outdoor physical activity in the early morning or late afternoon is recommended. Keep your face, arm and hands exposed to the sun.

However, it is important to avoid too much sun between 10am and 4pm and whenever UV levels are 3 or higher. At these times, use protection such as:

• shade
• clothing that covers your arms legs and body
• a hat that shades your face, ears and neck
• a broad spectrum (UVA and UVB) sunscreen of at least SPF (sun protection factor) 30
• sunglasses — preferably wrap around and labelled as 100% protective against UVA and UVB rays.

You can check the daily UV levels and protection recommendations for your area on SunSmart.

Sun protection alert — Sunsmartexternal link

May to August

It is recommended you take a walk or another form of outdoor physical activity in the hours around noon every day. Keep your face, arms and hands exposed to the sun.

If you are near snow, water or at a high altitude, you should always use sunscreen. Otherwise you can check when sun protection is recommended in your area on SunSmart.

You can get some vitamin D from food, but it is very difficult to get enough just from eating.

Food sources of vitamin D include:

• oily fish such as salmon, tuna, sardines and mackerel
• liver
• egg yolks
• mushrooms that have been exposed to UV light — simply place your store-bought mushrooms in the midday sun for 15 minutes, with the stalk facing up
• some margarines, dairy and plant milks and yoghurt have added vitamin D.

You can read more about how to get enough calcium and other nutrients to keep your bones healthy.

Eating well for healthy bones