Are you getting enough of the 'sunshine vitamin' this winter?
There is definitely a lack of sunshine in London at the moment. Have you thought about whether or not you are getting enough vitamin D? Studies suggest that more than 50% of adults in the UK have insufficient levels of vitamin D. It is difficult to get enough vitamin D from sunlight, particularly during the winter months (Oct-May).
But what role does vitamin D play in our bodies? And what dietary factors can we consider to naturally increase our vitamin D levels?
What is vitamin D?
Vitamin D is referred to as a fat-soluble vitamin but it is actually a hormone. A vitamin is a ‘nutrient’ that cannot be made in our bodies but helps our bodies to function. The body can synthesize vitamin D but only in the presence of sunlight.
How much Vitamin D should we be getting?
Although your body can make some vitamin D, the amount produced through sunlight will only last in your body for a few weeks. Therefore, you need an adequate amount in your diet to supplement levels over winter. The dietary recommendation for individuals not getting any sun exposure is 400 IU a day (10 micrograms). According to research, it is possible to get 8-9 mcg from a portion of oily fish.
It is difficult to exceed the recommended levels of vitamin D from your diet or through sunlight as your body only makes as much as it needs. However, according to NHS guidelines supplements should not exceed 25 micrograms (0.025mcg) a day. Taking vitamin D supplements over a long period of time can result in more calcium being absorbed than can be excreted, which can damage your kidneys.
Why do we need vitamin D?
Vitamin D is vital for good bone health because it promotes the absorption of calcium in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone.
Even if your diet is rich in calcium it cannot be absorbed efficiency without the presence of vitamin D. Other nutrients that play a role in bone health include phosphorus, magnesium, and vitamin K.
There are claims that low levels of vitamin D are linked to many illnesses including cancer and heart disease. Nonetheless, further research is required because in many cases it is unknown whether low levels of the vitamin have caused the disease.
Good food sources of vitamin D include:
Oily fish (sardines, salmon, pilchards, trout, kippers) are a good source of vitamin D. Evidence suggests higher levels of vitamin D and omega-3 fatty acids from wild rather then farmed fish). The government recommends having between 2-4 portions of oily fish a week (2 for children and during pregnancy and breastfeeding), due to levels of contaminants in some fish.
Cod liver oil contains significant levels of vitamin D (not recommended during pregnancy because of high levels of vitamin A).
Egg yolks, meat (particularly liver) and milk contain some but this varies between seasons.
Fortified foods including some breakfast cereals, dairy products and tofu (advised to check food labels to ensure vitamin D fortification and sugar content, foods containing more than 15g of sugar per 100g).
Adults over the age of 65, pregnant women or those who are breastfeeding may be advised to take a vitamin D supplement. Always consult your doctor if you are unsure.
How does cooking methods affect levels of vitamin D?
Various experiments show that frying oily fish in oil will reduce the vitamin D content. This is due to the fact that vitamin D is a fat-soluble vitamin and some will be lost in the cooking oil. Therefore, it is best to steam or bake fish and avoid using oil.
The role of exercise on bone health
To maintain good bone health you also need to consider the types of exercise you are undergoing. Weight bearing exercises including walking, running and dancing are effective ways to maintain strong bones when combined with a healthy diet. Dancing has many great health benefits, both from a physical and mental perspective.
Take a look at our latest published recipes, naturally high in vitamin D:
For more information on vitamin D or to discuss any dietary concerns you may have please contact me at firstname.lastname@example.org