Are you getting enough Vitamin D? (Updated)
As a nutritional therapist, lots of people ask me about Vitamin D. So what’s all the fuss about?
Well, people are right to be concerned – especially at this time of year (Sept to March). In the winter, we cannot synthesise Vitamin D (known as cholecalciferol) from sun exposure. This is because in the UK we don’t get adequate sun. And whilst it’s possible to get some vitamin D from foods, it’s totally insufficient. For example, an adult would need to eat salmon every single day to reach even the government recommended levels… which is not my idea of a varied diet. Plus many people never eat fish… You’re right in thinking that some cereals, yoghurts and margarines are actually fortified with vitamin D, however they only give you very very little Vitamin D generally – a drop in the ocean compared with what’s required.
The lack of vitamin D problem is so bad in Scotland – due to lack of sun exposure and a diet low in fatty fish – that academics called on the Scottish government (again) to take action to prevent worsening rates of Multiple Sclerosis, (MS). And that’s not to mention increases in the incidences of Rickets (softening of the bones) that we’ve all been reading about.
So – what is Vitamin D actually for?
There is mounting evidence that we can improve our bone health with taking sufficient Vitamin D – as well as calcium – to reduce the risk of fractures in those with osteoporosis in a number of ways, and to support healthy teeth and bones generally. Vitamin D plays an important part in preventing breast and bowel cancer. It also plays a role in supporting our immune systems, which can often take a battering over the winter when the cold & flu viruses are rampant. It also helps with other conditions including joint pains, arthritis, fertility, heart disease, diabetes and even those with allergies. Recently the Vitamin D Council showed that Vitamin D is involved in the regulation of 3 genes involved in autism. The ‘Ames’ study found that if children with autism are Vitamin D deficient then they’ll also have low levels of oxytocin, the hormone that promotes socialisation, and many studies of autistic children show them to be Vitamin D deficient.
In a study of 1600 people, those with low vitamin D levels are twice as likely to go on to develop dementia. (Littlejohns et al, 2014)
Research shows that men with prostate cancer tend to have lower levels of vitamin D, and men with healthy levels of vitamin D tend to have lower rates of death from prostate cancer – and less aggressive cancers. An 2012 experiment on men with early stage prostate cancer who took 4000 IU of vitamin D daily had fewer cancerous cells around the tumour.
Who is most at risk?
Those who lack of skin exposure to sun, ie pregnant women, breastfed babies under 2 years, people who cover their skin, those who don’t get outside very much, the elderly, those in care homes, and the house-bound, those people using a sunscreen year round – say in their moisturisers; as well as those with dark skin, and – unfortunately it gets worse with age, though its a big problem in the UK generally due to our geographic location! Not just being in Hertfordshire / Bedfordshire – in the UK we are obviously pretty far from the equator. The other issue is that by being generous with sunscreen we are reducing our skin’s ability to make Vitamin D. For example, SPF 15 blocks 93% of UVB rays, the type our bodies use to make Vitamin D. The UVA rays are the ones that could cause cancer… So it’s a bit of a balancing act.
Smokers are also less likely to be able to absorb Vitamin D (or calcium – or Vitamin C). On top of all that, our genes are known to affect our individual risk of Vitamin D deficiency.
Cardiovascular health: Blood pressure can rise when you’re Vitamin D deficient. Also if your cholesterol is said to be high then it may be an indication that your Vitamin D levels are low… so potentially worth getting a Vitamin D test.
Overweight people: Vitamin D deficiency amongst overweight people is well documented, and is thought it may affect organ health and calcium and phosphorous balance in these individuals.
What can I do? Sun, Supplements and Nutrition:
Try to get 20 mins exposure each day between 11am-3pm. If you happen to be leaving Letchworth for warmer climates, you will typically burn in less time than burning on a summer’s day in the UK. When you’re getting your safe sun – ideally reveal bare arms and legs, not just faces. I will be reminding people about this again in springtime, as the sun is so low and distant now that there is no possibility of vitamin D synthesis during the winter months. The advice from the US Vitamin D Council is to leave off the sunscreen for about half the time it typically takes your skin to burn… to get some vital rays before you block them out with sunscreen.
Tip: your body can make Vitamin D only when your shadow is shorter than your actual height.
Enjoy Vitamin D foods such as some of the oily fish ie salmon, (preferably wild salmon as it provides 4-5 times as much vitamin D as farmed salmon* though of course it’s more expensive though frozen is still fine); also mackerel, sardines, herring, trout and kippers.
So an 85g farmed salmon steak gives 425 IU or 20 mcg of Vitamin D whereas an egg yolk, small bowl of cornflakes or 75g chopped shiitake (not regular) mushrooms may give you about 40IU or 1mcg. 12 eggs a day isn’t a healthy way to get D! 2 slices of fortified bread may only give about 15% of the daily requirement, so eating lots of bread isn’t going to help Vitamin D without affecting your waistline!
The daily recommendation from the UK government for everyone age 1+ is 400 IU or 10 mcg daily, and even this is seen by many health experts – as very conservative. Under 1s are advised by the NHS to have 8.5-1 mcg daily. (For example The Endocrine Societies Guideline (USA) suggests that in order to maintain a healthy blood level of Vit D they recommend 1500-2000 IU daily for adults, the elderly and pregnant women).
If you choose to take a supplement, then choose one with the beneficial D3 form – cholecalciferol. The D2 form is often found in cheaper supplements is less effective, and in some cases research suggests, it might even be harmful. Vitamin D (in D3 form) is also available in drops and as a spray for those with a compromised digestion, or just for varied dosing if your whole family are taking it.
Some people cannot take Vitamin D – precaution is advised and if you are taking any medication or have any medical condition – please ask your GP’s advice before supplementing. There are particular warnings regards Vitamin D and some medications including but not limited to Bendroflumethiazide, and those who are breastfeeding.
Want to take a Vitamin D test to see if you’re actually getting enough? It’s quick and relatively cheap – just drop me a line & I can arrange it during your nutrition consultation.
A word about Vitamin K2
Vitamin K2 works closely with Vitamin D. and it’s best they’re taken together. Vitamin K2 helps our bones use calcium. Vitamin K2 is found in leafy green vegetables, high fat dairy foods, liver, and Japanese fermented foods such as natto. so if you are lactose intolerant veggie dodger – you may also be deficient in Vitamin K which is essential for our bone health. Many Vitamin D supplements include Vitamin K2 for this reason.
Can you help me to eat better?
Yes – and whilst there is no set amount of Vitamin D appropriate for everyone, but if you have any questions on its role in preventing osteoporosis and supporting the immune system, say – or any other area please don’t hesitate to get in touch for a nutrition consult.
Update (April 2018): Evidence continues to mount that vitamin D status affects many conditions, including but not limited to the risk of all-cause and cardiovascular mortality in dialysis patients, longer reproductive cycles in females, grip strength among elderly African American women at risk for osteoporosis, cardiovascular and all cause mortality in Caucasians, reduced duration of flu in infants, I could go on… The message is to get safe sun, eat oily fish if possible and take appropriate supplements.