It's summer, but are you still vitamin D deficient?
Vitamin D deficiency used to something that we only talked about in the winter months. Unfortunately, as the sun is only strong enough to stimulate vitamin D production here in the UK 3 to 4 months a year, typically from May through August, meaning most of us will be deficient.
During the summer months, your skin will make enough vitamin D to maintain good levels of it in the blood, BUT ONLY if you are outside for at least 20 minutes a day, without sunscreen, typically between 10am and 2pm in shorts and a tank top. Chances are, if you work in an office, you’re not getting enough.
How a vitamin D deficiency makes you feel
The symptoms of vitamin D deficiency are often vague and non-specific, such as tiredness, increased propensity for falling ill with coughs and colds, or general aches and pains. Deficiency is also linked to depression. Generally, however, it is completely asymptomatic.
If I have no symptoms why does it matter if I’m deficient?
Having the right levels of Vitamin D has a protective effect against many different diseases including cardiovascular disease, cancer, and osteoporosis. It supports your immune system helping the body fight infection such as flu or autoimmune reactions such as allergies, inflammatory skin conditions or if you have a specific disease such as IBD or MS. It is also helpful in supporting fertility and mood health.
How do you tell if you are deficient?
Vitamin D is most likely the most common deficiency out there. Approximately 60-90% of the UK population is deficient, dependent on where the lower threshold sits, which has recently been in increased from 50 nmol/L to 70nmol/L. The main reason for low Vitamin D is that, while it can be consumed through some foods, most of our supplies should be internally made. This process occurs in the skin when UVB sunlight hits the skin. So the further you live from the equator and the less sunlight you are exposed the more likely you are to be deficient.
If you fall into the following categories your risk of deficiency is further increased;
- People with darker skin. The darker your skin the more sun you need to get the same amount of vitamin D as a fair-skinned person.
- People who spend a lot of time indoors during the day. Especially if you’re housebound, work long hours in office or work nights.
- People who cover their skin with clothing or sunscreen all of the time.
- Older people have thinner skin than younger people and this may mean that they can’t produce as much vitamin D.
- Infants that are breastfed and aren’t given a vitamin D supplement. If you’re feeding your baby on breastmilk alone, and you don’t give your baby a vitamin D supplement or take a supplement yourself, your baby is more likely to be deficient in vitamin D.
- Pregnant women.
- People who are very overweight (obese).
If you have poor digestion. Vitamin D is a fat-soluble vitamin so if you have a gastrointestinal condition that affects your ability to absorb fat you may have lower absorption of fat-soluble vitamins like vitamin D as well.
It is easy to get your Vitamin D tested by GP with a simple blood test.
What should people look for in a Vitamin D supplement?
The European NRV (nutrient reference intake) is 5 micrograms or 200i.u. In the UK, concerningly, a recommended intake for the general population was not considered necessary but a recent governmental scientific review paper in 2015 indicated that this should be amended to 10 micrograms or 400i.u. You can safely take up to 4000i.u. per day without risking toxicity, so if you are deficient and looking to normalise your levels, a higher dose of 15micrograms/600 i.u. to 25micrograms/1000 i.u. would be recommended by most health professionals.
It important to take Vitamin D3 (Cholecalciferol) rather than D2. Vitamin D3 is the type of vitamin D your body produces in response to sun exposure, while vitamin D2 is not.