To make sure you get enough Vitamin D: Spend enough time outside in the summer months to ensure you are exposed to the sun without burning. The estimated time is 10-15 minutes without sun factor. Any longer, sun factor needs to be applied to avoid burning.
Following the SACN review of vitamin D 2016, Public Health England is now recommending that all adults and children over one year take a daily supplement of 10micrograms of vitamin D, this includes pregnant and lactating women. Although some people may achieve good sun exposure during the summer months and may feel they don’t need supplementation, the amount of vitamin D absorbed cannot be calculated. Those at greater risk of deficiency should certainly consider taking the supplement all year round. The recommendations state that babies under one should take an 8.5-10 microgram supplement unless they are having over 500mls of infant formula in 24hours
by Sara Patience, Registered Nutritionist, Registered Health Visitor
Vitamin D has been all over the news, with so much information about, and some misinformation, it is easy to get a bit confused about what you should be doing and why. I hope this blog helps explain what the current recommendations are in the UK, and why they exist.
Vitamin D is produced naturally when our skin is exposed to ultraviolet-B radiation from the sun. When it penetrates the skin it sets off a chain of events resulting in the production and circulation of vitamin D in our bodies.
You need vitamin D to control the amount of calcium and phosphate in our bodies required for strong bones and healthy teeth. When there is vitamin D deficiency the body can’t absorb calcium from the intestines and more calcium is excreted from the kidneys. Yet having the right amount of calcium in your blood is crucially important and highly regulated so your body has to get it from somewhere and when vitamin D can’t supply it, another hormone called PTH jumps in and draws calcium from your bones. Eventually, this results in rickets in children and osteomalacia, painful bones, in adults.
But Vitamin D does so much more than that! It controls over 200 cells and deficiency has been associated with auto-immune conditions and some cancers, SACN (2007).
The sun, not food, is the main source of vitamin D. In the UK we have a bit of a problem with that, in that the sun is generally in short supply. In a normal year, vitamin D is not available to us between around the end of September and the beginning of May. It was thought that during the summer months we would accrue enough vitamin D to see us through winter. We now know this isn’t happening well enough. Modern life has got in the way, we don’t make vitamin D when the sun has to shine through glass, through clothing, through sunscreen, if it’s cloudy or polluted. We spend a lot of time indoors. Skin colour is also a barrier to our bodies making vitamin D. The darker your skin, the longer it will take you to make vitamin D, with some research suggesting a 3, 10 times longer period of exposure to achieve the same vitamin D exposure as a light-skinned person. Some very light skinned people are not off the hook as they tend to cover up in the sun with clothing or sunscreen to prevent burning. Some women are covered for cultural or religious reasons. Some people now just cover up as they are worried about the effects of ageing or skin cancer. Also, some people cannot get out as much as they would like due to disability or frailty.
Vitamin D is found in oily fish, eggs and fortified foods such as cereals and margarine. In the UK, milk is not a good source of vitamin D as it is not fortified.
It is estimated that we cannot eat enough foods containing vitamin D to become sufficient. A German study suggests that less than 10% of vitamin D requirement is met through foods (Sichert-Hellert et al 2006). It is also advised that girls and women of childbearing age, do not eat more than 2 portions of oily fish a week due to the potential pollutants in the fish.
The new SACN vitamin D guidelines do not make specific recommendations for pregnant and breastfeeding women as ALL adults are now recommended to take 10micrograms of vitamin D daily. As babies are born with the same vitamin D status as their mums, it seems sensible for pregnant to ensure they take the recommended dose each day. Breastfeeding mums will want to top up their vitamin D levels and should also consider following the new guidelines.
Vitamin D in supplement form can build up in your body and be toxic in large amounts, so do not exceed the amount you have been advised to take by your health professional. This is not the case with vitamin D obtained from the sun as your body can deal with any excess when obtained this way.
Some women are surprised to hear that breast milk is not a good source of vitamin D. Before saying more, breast milk is, of course, the best food for baby, bringing many health benefits to both baby and mum, but that doesn’t mean we should ignore the evidence.
Human milk contains only 15 – 50 IU/L vitamin D, with an average of 25 IU/L, (0.62mcg), which is not sufficient to meet the requirements of the human infant (Gartner et al 2003, Callaghan et al 2006, Leerbeck et al 1980).
The reason for this is the same as we discussed above, modern life! We no longer live outdoors, semi-naked, without buildings or cars or pollution. In fact, we don’t even have to go back that far, many people today don’t even go out for a walk, children don’t play in the street, babies are covered completely in their pushchairs as if they would vapourise if a ray of light touched them and many people do not go out without covering themselves in sunscreen.
Of course, we have to be sensible in the sun, neither you or your children should burn in the sun, but we do need some exposure, during summer months, during a hot part of the day, for 10 minutes or so on a reasonable part of our arms, legs or body, (face and hands alone are not enough). If you are fair skinned you can have two or three shorter exposures to the sun in one day, you don’t need to burn. Be more careful when you go abroad to a hot country. Babies should not be exposed to the sun and you should follow the supplement advice given to you by your midwife, health visitor or family doctor. However, they don’t need to be kept in a dark place, just sensible precautions.