HealthInfo Canterbury
How to get your daily vitamin D
We need vitamin D for strong bones and muscles and general health. It helps your body take in enough calcium from the food you eat.
Your body makes most of the vitamin D it needs in your skin when exposed to direct sunlight. Sunlight through glass doesn't 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 alone isn't enough.
Your body can't store much vitamin D, so you need to keep topping it up.
Being low in vitamin D can cause muscle aches and thinning bones leading to osteoporosis.
Risk factors for being low in vitamin D include:
- spending most of your time indoors such as in a rest home or hospital
- having dark skin
- being pregnant or breastfeeding, as you need more vitamin D at these times
- covering most of your skin when outdoors
- having to avoid sunlight because of other health conditions (such as skin cancer) or medications that you're taking.
Getting enough vitamin D
Sensible sun exposure is the best way to get your vitamin D. For most people, this is about 20 minutes each day. The amount of sun exposure you can have safely will vary depending on several factors such as:
- your skin colour
- if you're taking medications – some medications make your skin more sensitive to sunburn
- where you are in New Zealand, the season and the time of day
- certain medical conditions.
General recommendations for New Zealand depend on the time of year:
- September to April – Sun protection is recommended (shade, clothing coverage, a hat that shades your face and neck, sunscreen, sunglasses), especially between 10 am and 4 pm. A daily walk or some other form of outdoor physical activity in the early morning or late afternoon is recommended. Sunscreen reduces the amount of vitamin D you make, and is generally not needed in the early morning or late afternoon.
- May to August – Some sun exposure is important. A daily walk or another form of outdoor physical activity in the hours around noon with face, arms and hands exposed is recommended. Sunscreen reduces the amount of vitamin D you make and is generally not needed at this time of year unless you are on snow or water.
Food
You can get some vitamin D from food but it's very difficult to get enough just from eating. Food sources of vitamin D include fatty fish (salmon, herrings, mackerel), liver and eggs. Some margarine, milks and yoghurt have added vitamin D.
For more information on how much to eat of these foods, see Eating well for strong healthy bones.
Written by HealthInfo clinical advisers. Page created February 2020.
Review key: HIOSP-24517
