Why everyone should be talking about vitamin D

Perhaps I've been living under a vitamin D shaped rock for the last few years, but I can honestly say that until I met Juliet's friend Jo O'Reilly (a fully qualified dietitian) a couple of weeks ago, I had received zero information on the importance of vitamin D supplements in early years. My kids spend a lot of time outside and fortunately aren't fussy eaters, so they have what I like to think is a healthy balanced diet (on most days at least!).  But when I found out from Jo that the government has advised parents to provide children under the age of 5 with vitamin D drops or supplements, I must admit I was pretty surprised that I'd missed this information! Juliet and I figured that if I didn't know, then lots of other mums out there don't either... not everyone is lucky enough to have a dietitian friend who can point them in the direction of the supplement aisle! We asked Jo to contribute a post for us on why vitamin D is so important, not just in early years but through adult life too.


So its official, winter is here! The clocks have gone back, trick or treating was a success and there were lots of oohs and aahs from the town's firework displays. Other than the Christmas count down and endless casseroles we seem to be eating in our house, a Dietitian’s mind turns to the much anticipated vitamin D recommendations from the Scientific Advisory Committee on Nutrition (SACN). 

Johanna (Bates) O'Reilly, Dietitian

Johanna (Bates) O'Reilly, Dietitian


So why is vitamin D so important? 

As a pro-hormone it is vital to help the absorption and regulation of Calcium and Phosphate in the body. So it’s a key component when growing strong bones, teeth and keeping our muscles and bones healthy. Mild deficiency can result in tiredness and general aches and pains and a general sense of feeling unwell, which is never a good look during the festive season! However, more worryingly, deficiency in children can lead to being more prone to infections, delayed tooth growth, a soft skull, stunted growth, bowed leg bones, bone pains and muscle weakness, with the latter symptoms known as Rickets. 

This explains why parents have been advised to provide all children under the age of 5 with Vitamin D (ideally vitamin d3) drops or supplements to prevent this condition, which saw a marked incidence increase between 2007-2011. I know that I’ve often encouraged fellow mummies to make a trip to the supplement aisle. And it appears that it's not only young children that are seen as at high risk groups. Many of us, from toddlers to the elderly, appear to be at risk of being deficient, particularly during the winter months. The latest National Diet and Nutrition Survey found that mean intakes of it vitamin D were lower across all ages and gender groups compared with previous surveys, apart from women aged 65 and over (this may be due to women taking calcium and vitamin D supplements post-menopause perhaps). 

Deficiency in adults results in many of the same symptoms as those seen in children but instead of Rickets, adults are at risk of Osteomalacia, which is again, softening of the bones. As we do most of our bone growth and bone thickening in the first 20 years of our lives it is essential that as children and young adults we absorb all the Vitamin D and Calcium we can get! 

Known as the ‘sunlight’ vitamin, the UK's main source of vitamin D is from the UVB rays between the months of April until September. During these summer months it is hoped that we can absorb enough UVB rays to make all the vitamin D we need for the entire year in the skin. The amount of vitamin D we make also depends on how long the exposure lasts for and how well each individual’s skin makes the vitamin D. So I'm pretty sure the last time I absorbed an adequate amount was mid-summer 2014-2015 during maternity leave when I was outdoors most days and luckily enjoyed a holiday abroad! 

Other health messages such as protecting our skin from the sun has often meant that children in particular are covered up and slathered in Factor 50 as soon as the sun pops out to play, therefore reducing our exposure. Teens are spending more time inside on computers, adults spend longer working hours in offices and the elderly are also often indoors, especially those in care homes. However, the answer clearly wouldn't be to forgo the sun cream and bake ourselves during our lunch break, as this too presents a risk to our health. Those with darker skins have less absorption so coupled with the lifestyle factors already mentioned, they are considered an at risk group and advised to take vitamin D supplements all year round. 

Can't we get enough from our diets? 

Well the answer is there are very few dietary sources and some are unlikely to be eaten on a daily basis. The main vitamin D sources are oily fish, eggs and margarine, red meat and liver along with fortified breakfast cereals. Some companies have also started including vitamin D in bread, bread rolls and in some yoghurts. In recent times, breakfast cereals seem to have ‘copped a bad rap’ with many reports on those with high 'added' sugar contents. Many people, particularly parents can be confused on whether to give cereals to our little ones or not? 

Opting for fortified cereals, ideally ones that contain less than 5-8g/100g carbohydrate 'of which sugars' and are fibre rich, such as Weetabix, Oatabix, Shredded wheat or plain instant oats, means your child starts off the day with a dose of vitamin D, along with B vitamins, iron and calcium. You can also mix low fibre cereals such as rice crispies or cornflakes (which are also fortified with vitamin D) with higher fibre cereals. The milk added to the cereal also contains calcium, protein, phosphate and iodine, which make this a good start to the day for young and old. However, even by my calculations, a bowl of fortified cereal may only provide between 1.5-2ug (micrograms) of vitamin D which is only 15-20% of the recommended 10ug/day (400iu/day). 

Therefore, while it remains important to include a range of dietary sources of vitamin D, all adults and children over the age of one should consider taking a daily supplement containing 10ug (micrograms) of vitamin D per day especially during autumn and winter. All babies under one year should be given a daily supplement of 8.5-10ug (micrograms) unless they have more than 500mls of fortified formula milk.


Jo O'Reilly

Jo O'Reilly (known professionally as Johanna Bates) is a dietitian, HCPC registered since 2008. She is also a massage therapist, reflexologist, beauty therapist and mummy. Follow Jo on twitter.