The secrets of Vitamin D | Why you need to supplement


Remember when you were young? Back then Vitamin D was an insignificant vitamin that kept your bones strong. Way down the list after the 'important' vitamins - C, the B's, A and E. We were shown pictures of poor third world children with bow legs and rickets who clearly lacked it but were never actually told how to avoid a similar fate. 

Now all these years later we find that vitamin D is the most important of them all. The possible cure for almost everything. And, confusingly, that it's not really a vitamin. The thing is that they have now found that nearly every tissue and cell in your body has receptors for vitamin D. That makes it a hormone instead – most confusing. But either way, you really, really need it. Without sufficient levels you just don't function as well as you should.

Vitamin D without the supplements
Vitamin D without the supplements

The problem here is that human beings just don't make enough vitamin D naturally, by ourselves. So you have to boost your levels through your diet and by going outside in the sunlight. Failing that (and as a sensible insurance policy for the days when you don't get enough from food or the sun), we should take a supplement. Many of us fail on all three counts. A whopping 3/4 of the UK population are estimated to be low in vitamin D.

Vitamin D in foods

The best sources of Vitamin D are fatty fish, like salmon, sardines, mackerel and tuna. Cheese and egg yolks are good, as are mushrooms and raw (unpasturised) milk and any vitamin D fortified foods (usually cereals, orange juice and dairy products).

Sunlight: the ultimate vitamin D source

The sun is the best source of vitamin D. Aim for at least 20 mins a day outdoors, and try to keep your arms, legs or face exposed. For a guide on how to pick a safe SPF, check out our recent blog post on the topic. The best time for light metabolism for the body is before 9am or two hours before sunset.

Once you have eaten the foods, or taken in vitamin D through your skin, your kidneys and liver will turn it into an active form, D3, that the body can then use.

Research has now shown that low levels of vitamin D are associated with all sorts of health problems. Low levels increase the risk of Alzheimer's by 77% and of non-Alzheimer's dementia more than 20 times. They make you 91% more likely to develop 'pre-diabetes' and twice as likely to get full blown Type 2 diabetes. They are associated with depression, cancer and auto-immune disease, and increased risk of strokes and heart attacks. Vitamin D regulates genes that control metabolism, immunity and cell development. It supports the heart and the cells of the brain. It also reduces blood pressure.

You can see why you really must take it.

Sunny days keep the doctor away
Sunny days keep the doctor away

Vitamin D supplements: What is the right level to aim for?

You can ask your doctor for a Vitamin D3 test (25-hydroxyvitamin D) to find out whether you need to supplement. You want to aim for a level of 50 ng/mL though personally, I keep mine higher. 2,000 IU/day is a minimal dosage to reach those levels. (You need to take 100 IU of additional D3 for each 1 ng/mL you want to raise it). 3,320 IU daily was found in one research study to reduce triglycerides by 13.5%. Weight loss and better HDL cholesterol levels were additional side effects. Everyone is different though, so it's important to get yourself tested regularly, at different times of year, and keep track of your levels.

Another point to make is that different brands of vitamin D supplementation work differently for everyone. Some may find pills effective. For me, only the liquid Vitamin D3 seems to work, and there again, some brands boost my levels better than others. I take it in spray form, under my tongue. If you can, get a supplement that combines D3 with K2 and always take vitamin A alongside your D because without those two additions, the body struggles to synthesize vitamin D efficiently. If you can, take your daily dosage with the meal that is likely to contain the most fat. This ups the body's absorption optimally.

Times to pay attention. When do your levels drop most?

Winter Time:

It is UVB rays that enable you to make the vitamin D your body needs. So when the sun disappears, your levels automatically drop. Make sure you supplement daily during the darker months of the year. Similarly, if you stay indoors most of the time year round – whether in an office or your home – you won't be getting the sunlight exposure you need to keep your vitamin D levels up. Walk outside regularly – it doesn’t need to be hot sunshine.

Getting older:

Age reduces the amounts of Vitamin D your skin produces even when you go in the sun regularly.  Again, supplement more as you approach middle age.

Getting heavier:

The more you weigh the more you need to supplement. Vitamin D is a fat soluble vitamin, and body fat soaks it up fast. And if you are super-fit your muscle mass can do the same thing. Up your dosage.

Skin tone:

Pale skinned people apparently need 10 times less sun exposure than darker skinned people to produce the same amounts of vitamin D. (See our sunscreen post and be careful how you protect yourself.)


Vitamin D levels drop dramatically when you are pregnant. Your body needs additional levels for your baby's health too... so supplement daily.

Get your vitamin D levels sorted and hopefully you will resolve many of your health issues in the process... or at the very least improve them.  Get outside, soak up the sunshine, and let me know how you get on?