What is Vitamin D?
Vitamin D is also known as the ‘sunshine’ vitamin due to most of our intake being from the glorious sun. Vitamin D is made under our skin when we are in the sunlight and although we call it a vitamin, it’s more like a steroid hormone that we make in our body. The amount of Vitamin D our body makes is dependent on how strong the sunlight is, with over 80% coming from UV sunlight. In theory we should make more when the sun is at its most intense, however, not all of us are lucky enough to live in hot sunny climates throughout the year.
In 2016, The Scientific Advisory Committee on Nutrition (SACN) produced a report on Vitamin D and health looking at the importance of the vitamin and to see if we are getting enough in the UK. From this report Public Health England (PHE) updated their guidance for our recommended daily intake of 5 micrograms (ug) to increase to 10ug. However, on average the UK are only getting approximately 2.8ug per day!
Why do we need Vitamin D?
Vitamin D is important for protecting muscle strength and can prevent rickets in children and osteomalacia in adults. Vitamin D helps to control the amount of phosphate and calcium in our bodies, so even if your diet is high in calcium, without enough Vitamin D you cannot absorb the calcium into your bones or cells. Phosphate and calcium are needed for healthy bones, teeth and muscles. You may have read in some places that Vitamin D can help with depression or more recently our immune system against Covid 19. Even though there are many studies taking place in relation to these topics, there is not yet sufficient evidence for SACN to include this in their report. Watch this space though, in the world of nutrition new things are being discovered all the time!
Sources of Vitamin D:
Vitamin D is naturally present in foods such as; oily fish (salmon, sardines, mackerel, fresh tuna etc), red meat and egg yolks. However, if you follow a plant based diet you can contribute to your Vitamin D intake with foods such as sun-exposed mushrooms and fortified foods which can include margarine, tofu, plant based dairy alternatives and cereals. But don’t start bulk buying the mushrooms just yet, there are not significant amounts of Vitamin D in these foods to ensure we get the recommended intake. For example: you would need around ten eggs to get the recommended 10ug and for those of you who are vegan, although mushrooms are a Vitamin D source, you should ensure that they are grown under sun or UV light.
During the summer months (April to September) a balanced diet with moderate skin exposure to sunlight should help most of us get enough Vitamin D. However, in the winter months (October to March) PHE have recommended that we may want to consider taking a Vitamin D supplement to help us reach 10ug. Don’t panic though, this doesn’t mean we are all at risk of a Vitamin D deficiency but there are certain groups who may be more susceptible to having low vitamin D levels, see below.
Symptoms of Vitamin D Deficiency:
Symptoms of vitamin D deficiency can include:
- Bone pain
- Muscle aches
However, if these symptoms continue even after consuming vitamin d supplements please see your GP as they are also attached to other deficiencies and illnesses.
Who is at risk of being low in Vitamin D?
- Babies and young children
- Pregnant women and breastfeeding mothers
- People over 65 years because their skin is not as good at making vitamin D
- People with darker skin tones
- People who cover most of their skin or spend little time outside during the summer
Why is Vitamin D important if you are pregnant?
When you are pregnant the foetus is entirely dependent on the mother for vitamin D, due to some forms not actively crossing the placenta. In the UK it is recommended that your intake during pregnancy is 400IU (or 1000IU if you are at risk of deficiency).
The benefits to taking Vitamin D during pregnancy are:
- Reduce the risk of eclampsia by 38%
- Increase birth weight
- Maintain maternal and fetal bone health
- Reduce the risk of long-term rickets and bone deformities
A lot of vitamin D sources are animal based foods/products and so it is important to note that Vitamin D supplements for vegans and vegetarians may be slightly different. If you are vegan then opt for lichen-derived Vitamin D3 as these will be suitable, but it is advised to always check the label. Vitamin D2 is also suitable for vegans but this may be less biologically active than Vitamin D3 we make ourselves or from animal products.
Top tips for supplementing Vitamin D:
- Avoid taking more than one supplement containing 10ug of Vitamin D per day – not only is this unnecessary but it could cause some harm in the future. If you are already taking multivitamins check if they already have vitamin D in before supplementing.
- If you are not exposed to a lot of sunlight in summer months or you keep your skin covered throughout the year then it may be worth considering taking a supplement all year round.
- When exposing skin to sunlight please be careful, this does not mean you should put your skin health at risk. 30 minutes of your legs and arms being exposed to the sun should help you make some vitamin D.
- Vitamin D and Vitamin D supplements absorb well with fat so try and take your supplement at meal times.
- It is important to note that this is public health guidance and to remember that all our beautiful bodies are unique. If you have specific questions or are concerned with your Vitamin D intake contact your doctor, health visitor or a Registered Dietitian/Nutritionist.
This article was written by our guest writer Sarah Jackson.Sarah is a Registered Nutritionist with the AfN and a Sports Nutritionist with the SENr after graduating from her post graduate in Sport and Exercise Nutrition. Sarah has 10 years experience as a nutritionist, ranging from the NHS, food industry and her private 121 clinic where she works with clients ranging from weight management to improving athletic performance.
You can find out more about sarah at:
@sarahjnutrition on Instagram or her websitewww.nutribloom.co.uk