I’ve talked elsewhere about the key nutrients for immune health but vitamin D deserves its own blog. We’ve typically been taught that vitamin D is for strong bones but its role in your health extends beyond bone.
The many roles of vitamin D in your health
Regulation of the immune system
Vitamin D plays a critical role in the regulation of your immune system. Numerous observational studies link low levels of vitamin D levels with allergies, respiratory infections, certain cancers, and particularly autoimmune conditions such as multiple sclerosis, rheumatoid arthritis, Crohn’s disease, Lupus, auto-immune thyroid disease and others.
By ensuring you have adequate Vitamin D, you are helping your immune system regulate its activity (i.e. not overactive or underactive) and keep inflammation in check.
Bone health and the regulation of calcium
Vitamin D is essential for bone health via its role in regulating calcium and phosphate balance in your blood and your bones. Vitamin D promotes the absorption of calcium and phosphorous from your foods, making them available for incorporation into your bones. This is extremely important for bone density and overall bone health.
Low levels of vitamin D are implicated in diseases such as osteoporosis along with an increased risk of falls and fractures. The “classic” sign of low vitamin D is rickets, seen in children whose growing bones are dependent on adequate vitamin D along with the nutrients for bone formation.
Regulation of cell metabolism
Along with its role in immune regulation, vitamin D also plays a role in cellular metabolism and cell growth, helping to maintain a normal cell lifecycle. So essentially, ensuring that old cells die and new cells form as they should.
Fertility and healthy pregnancies
In females, vitamin D is required to support the implantation of a fertilised egg, and support the skeletal development of the foetus. Vitamin D in males is just as essential. It may support the healthy production of sperm.
Are you getting enough vitamin D?
If you haven’t had your vitamin D levels checked by a blood test then how do you know if you have adequate vitamin D?
In Australia, the prevalence of deficiency in adults is estimated at 22% in men and 39% in women. This is an average and the rates are even higher for those in the southern states and low vitamin D is even more common in winter than summer (not surprisingly). It’s worth noting that adequate levels of vitamin D are not necessarily enough for optimal health. (You can read more about interpreting blood tests here).
So, what factors influence your vitamin D levels?
Do you work indoors all day?
If you arrive to work in the dark and leave after dark (much more common in winter) then it is likely you will find it difficult to get adequate levels of vitamin D throughout the colder months.
Do you use sun protection every time you are outdoors?
By using sun protection you reduce your risk of skin cancers and this is vitally important, particularly through those peak times during the day. However, if you cover up all the time, you reduce your ability to absorb vitamin D from the sun and therefore have to rely primarily on your diet (and dietary sources are limited). Furthermore, the darker your skin, the harder it is to make vitamin D from sun exposure.
How healthy are you?
Vitamin D is metabolised and converted to its active form, vitamin D3 (cholecalciferol) via some complex biochemistry dependent on the healthy functioning of your liver and kidneys. Alcohol, smoking, certain medications, or conditions causing malabsorption of nutrients from the gut may all impact your vitamin D levels.
How can you boost your vitamin D levels?
Enjoy sun exposure for 5-15 minutes every day
Exposure of arms and legs to the sun should ensure you are getting adequate vitamin D. Make sure you are safe in the sun though and avoid those peak times – you are looking to get Vitamin D not sunburnt. Of course, if you are at high risk of skin cancer, even small amounts of sun exposure may not be appropriate for you.
Incorporate good quality meat and oily fish into your weekly diet
Small amounts of vitamin D can be found in animal foods such as beef, veal, liver, eggs, butter and oily fish (such as salmon, sardines and tuna). Some foods are also fortified with vitamin D such as milk and other dairy products. Vegan sources include mushrooms if they have been exposed to sunlight.
Be kind to your liver and kidneys by making healthy dietary and lifestyle choices
Support your detoxification pathways and improve your liver and kidney function by eating a diet rich in vegetables, fruit and good quality meat and fish, as well as drink plenty of water. Drink alcohol in moderation (if at all) and if you smoke cigarettes, now would be a good time to think about quitting (and not just for your vitamin D levels of course).
Talk to me about whether you would benefit from a vitamin D supplement
Vitamin D is a fat-soluble vitamin stored by the body so there is the risk of toxicity if you take too much. Therefore, before you think about supplementation, make sure you talk to your health care practitioner. I will likely suggest we test your vitamin D levels and assess their adequacy based on your health and the time of the year. That way, we have better information to work out the best dose for you (one size doesn’t fit all).