How Much Vitamin D Should I Take?
As many as 60 percent of the UK population is Vitamin D deficient and low levels have been linked to serious health problems in later life.
One of the most popular questions I get is ‘So how much Vitamin D should I take?‘
Vitamin D is a fat-soluble vitamin which can either be ingested in food or manufactured by the body as a result of sunlight falling on the skin. People who feel they do not get enough sunshine often choose to augment their diet with extra Vitamin D supplements. Vitamin D is also vital for the proper absorption of calcium and the use of phosphorus to form healthy bones and teeth.
The Government in the UK has issued public health advice stating that everyone should consider taking Vitamin D supplements in Autumn and Winter. The dosage recommended is 10 micrograms (400iu) of Vitamin D per day. There is concern that is may not be achievable through diet and sunlight alone and people should therefore get their Vitamin D intake from supplements.
Can’t I get Vitamin D from my diet or from the sun?
Limited amounts of Vitamin D are found in foods such as oily fish, eggs and fortified foods but for most people, the majority of their Vitamin D is made from the action of sunlight on their skin. Since we have a lack of sun for the most part of the year in the UK, there is a real concern that people just aren’t reaching the optimum levels necessary for good health.
What should my Vitamin D levels be?
Vitamin D levels are checked by a blood test. Vitamin D is measured in nanomoles per litre (nmol/L). You can ask your GP for a Vitamin D test to find out what your level is.
The UK Department of Health advises the following measurement guidelines:
>50nmol/l = adequate
25-49nmol/l = insufficient
<25nmol/l = deficient
We do know that the majority of people in the UK fall into the deficient category.
How much Vitamin D should I be supplementing with?
You may have had your Vitamin D levels tested or you suspect that you are deficient and you want to boost your levels. What dosage should you take?
The answer to this is complicated due to the difference between all our lifestyles. How long to you go out in the sun for? How often do you eat oily fish? Do you use a total block sunscreen, what are your current Vitamin D levels etc.
We know that the minimum you should be taking is 10mcg (400iu). However this dosage may not be enough for people who are deficient or those who may be in the “at risk” groups. These people need to be more careful about ensuring they get a good intake of Vitamin D.
Who are in the high-risk group of being Vitamin D deficient?
- Infants or children aged under 5
- pregnant and breastfeeding women, particularly teenagers and young women
- people over 65
- people who have low or no exposure to the sun, for example, those who cover their skin for cultural reasons,
- who are housebound or confined indoors for long periods
- people with darker skin, for example, people of African, African-Caribbean or South Asian family origin
All things considered, a daily Vitamin D supplement intake of 25 – 100mcg (1000 – 4000iu) should be enough to ensure good blood levels in most people.
How much Vitamin D is too much?
We don’t need to worry about taking too much Vitamin D through our diet as the amounts are minimal. We also don’t need to worry about getting too much from the sun as the body has a feedback mechanism that prevents too much Vitamin D from being made through the skin. Vitamin D toxicity can however occur through overuse of supplementation.
This is known as hypervitaminosis D. It is exceptionally rare and usually occurs in extremely high long-term doses of Vitamin D supplements. The main consequence of Vitamin D toxicity is a build-up of calcium in your blood. The Institute of Medicine and HFMA (Health Food Manufacturers Association) recommend the upper safe limit of 100mcg (4000 iu).
Be wary of buying a Vitamin D supplement online which is higher than this dosage and does not give any mention of guidelines. If you are considering taking a higher dosage than 4000iu, you must speak to your Doctor before purchasing.