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Vitamin D

Vitamin D is needed for healthy bones and muscles, especially in children and the elderly. There is also evidence that vitamin D may reduce the risk of some types of cancer, particularly colorectal and breast cancers. Your skin produces vitamin D when exposed to sunlight, but you don’t need a tan to get benefits from the sun.

The amount of sun exposure needed to produce enough vitamin D depends on:

  • age
  • diet
  • skin colour
  • where you live
  • how strong the sun is

For most people, just a few minutes out in the sun – the short, casual exposure you get while going about daily life – will be enough. Even with the benefits of vitamin D, we recommend that you still practice SunSense.

Getting your vitamin D from your diet (many foods are fortified with vitamin D) or by taking vitamin supplements is safer than UV-ray exposure.

  • Our recommendation

    Due to our northern latitude and because the sun’s rays are weak in the fall and winter, talk to your doctor about whether taking 1000 international units (IU) a day during fall and winter months is right for you.

    Babies who are exclusively breast-fed may be at risk of vitamin D deficiency, which is why experts recommend they be given a vitamin D supplement of 400 IU a day.

    Who’s at higher risk?

    You’re probably not getting enough vitamin D if you:

    • are over 50
    • have dark skin
    • don’t go outside very much
    • wear clothing covering most of your skin

    If you are in one of these groups, talk to your doctor about whether you should take a vitamin D supplement of 1000 IU every day, all year round.

    Can you have too much of a good thing?

    We don’t recommend taking any more than this amount because too much vitamin D can be harmful. Current evidence suggests that taking this amount will help reduce your risk of cancer but with the least chance of harm.

  • Getting the right amount of vitamin D

    For most adults, taking a supplement of 1000 IU a day won’t be a problem. But there is most likely an optimal range of vitamin D – having either too little or too much can cause health problems.

    Side effects of too much vitamin D

    The most common side effect of having too much vitamin D is high calcium levels, called hypercalcemia. Some early symptoms of hypercalcemia include:

    • nausea
    • vomiting
    • poor appetite
    • weakness

    Talk to your doctor if you are experiencing any of these symptoms.



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