11 surprising things you might not know about vitamin D
By Martha Roberts
03/2017
Many of us know it as the 'sunshine' vitamin that gives us strong teeth and bones.
But there's much more to it than that, which is why it's currently the vitamin on everyone's lips.
Research shows that this vital nutrient can help in a range of ways, from boosting immunity to potentially reducing the risk of a range of chronic illnesses.
Here are 11 vitamin D facts that may surprise you.
1. Many of us aren't getting enough
'Evidence from the latest UK National Diet and Nutrition Survey shows that 1 in 5 adults aged 19 to 64 years have low blood levels of vitamin D, indicating a risk of deficiency,' says Dr Emma Derbyshire, leading nutritionist and advisor to the Health Supplement Information Service.
She adds: 'As we do not seem to be getting the amounts of vitamin D that we need from dietary sources, taking a supplement could help to 'top these up' and reduce deficiency risk.'
2. We've even seen a rise in rickets
A 2014 study found that hospital admissions due to rickets (a condition, commonly caused by a lack of vitamin D, that affects bone development in children) was the highest it's been in England since the 1960s.
Dr Derbyshire says: 'This is mostly being seen amongst children who are not getting enough sunlight, or enough milk and dairy products and are physically inactive.
'Many children are also confined indoors and do not play outside as they used to, which means that they will not be getting as much vitamin D from sunlight.'
3. Sunshine and supplements are the primary sources, not diet
Vitamin D can only be found in a small number of foods. One of the main sources is oily fish such as salmon, mackerel, herring and sardines.
Dr Derbyshire explains that we tend to under-consume oily fish in the UK. 'Mean consumption of oily fish is well below the recommended one portion (140g) per week, with UK adults eating just 54–87 grams per week, so less than half of what's recommended,' she says.
At the same time, the NHS advises the general public to have 'no more than four portions' of oily fish a week - or 'a maximum of two portions' for pregnant or breastfeeding women - because of low levels of pollutants that can build up in the body.
Other dietary vitamin D sources are red meat, eggs, some breakfast cereals and some yoghurts which have been 'fortified' with the vitamin. Milk contains small amounts, but this varies during the seasons.
Overall, our daily requirement of vitamin D cannot be met through diet alone.
Geeta Sidhu-Robb, nutritional therapist, raw food chef and founder of Nosh Detox says: 'The body takes about 10 per cent of its vitamin D from food and makes the rest from sunshine and supplements.
4. Cloud cover, sunscreen and skin tone can affect the body's ability to make vitamin D
Vitamin D is known as the 'sunshine' vitamin because it's produced in the skin when exposed to the sun's rays.
Geeta Sidhu-Robb explains: 'The sun's ultraviolet B (UVB) rays interact with a protein called 7-DHC in the skin, converting it into vitamin D3, the active form of vitamin D.'
However, the sun is only strong enough in the UK for our bodies to produce vitamin D from around late March to the end of September and, even then, various factors can affect our ability to make vitamin D.
'Limited sun exposure, coupled with sunscreen use, can prevent us replenishing our vitamin D status even during the summer months,' says Dr Derbyshire.'For these reasons, it is worth topping up with a supplement, especially during the winter months, or if we have a particularly bad summer or don't go on holiday.'
People with darker skin are also advised to consider a supplement all year round, as greater levels of melanin in the skin slows down production of vitamin D.
5. It's the only vitamin supplement the government advises for everyone
The Department of Health currently advises that everyone over the age of five (including pregnant and breastfeeding women) should consider taking a daily supplement containing 10 micrograms of vitamin D, particularly between October and March.
Children aged between one and four years should have a daily 10mcg vitamin D supplement all year round, while babies under one year who are exclusively or partially breastfed should have a daily 8.5-10mcg vitamin D supplement.
Dr Derbyshire says the new guidelines 'also recognise that some groups may have a greater risk of vitamin D shortfalls, including those who rarely go outdoors, such as the frail, housebound, those living in care homes or those wearing clothes that cover up most of their bodies.' The government recommends these groups should take a supplement all year round.
If you are considering taking a supplement, you should speak to your pharmacist for more information. Fultium Daily D3 is an easy one-a-day vitamin D supplement, which is only available from your pharmacist. It has been formulated specifically to meet the Scientific Advisory Committee on Nutrition's (SACN) and Public Health England's (PHE) new recommended vitamin D guidelines.
6. Calcium needs vitamin D to be absorbed in the body
We all know that calcium is essential for building strong bones, helping to ward off osteoporosis. But, what you might not know is that vitamin D is what actually enables our bodies to absorb calcium from food.
So, even if you're getting enough calcium in your diet, it will go to waste if you haven't got sufficient levels of vitamin D.
7. It comes in two different forms
Vitamin D3 (cholecalciferol) is the form that's made by our bodies when the skin comes into contact with sunlight. It is also found in animal food sources such as red meat and oily fish.
Vitamin D2 (ergocalciferol) is the form found in vegetarian and vegan supplements and is produced by plants in response to UV light.
Vitamin D3 has been found to be better utilised and absorbed by the human body.
8. We're starting to put it in our food
Some manufacturers have started adding vitamin D to our foods. For example, M&S now fortifies all of the bread in its pre-packed sliced bread sandwiches with vitamin D. Vitamin D levels in yeast naturally increase when the yeast is exposed to UV light and the vitamin is then transferred to the bread.
Dr Derbyshire says: 'There have been some very good trials looking at vitamin D fortification, especially in bread. Further work is needed to look into which forms of vitamin D are best used (typically D3), the levels of fortification needed to have measurable benefits and the realities such as how much bread would we need to eat each day.'
9. Vitamin D deficiency has been linked to fatigue and depression
'Fatigue is a very generalised and subjective symptom linked to many other diseases,' explains Dr Patricia Macnair, specialty doctor in medicine for the elderly at The Royal Surrey County Hospital, Guildford. 'Low vitamin D levels are common among those who complain of fatigue, but science has yet to unravel whether the low vitamin D level itself plays a part, or whether the fatigue simply reflects underlying conditions. However, as with other conditions, it makes sense to check vitamin D levels and give supplements if they are low, to try to normalise the patient's physiology as far as possible. '
She adds: 'Although we think of vitamin D as a vitamin with action on the bone, we now understand that it works as a hormone on various systems in the body, and that there are vitamin D receptors in the brain. It appears to modulate neurotransmitters including dopamine and serotonin which both play a part in mood. So it makes sense to wonder if vitamin D may affect depression.
'There are a growing number of studies looking at possible links between vitamin D levels and depression, but the picture isn't very clear yet.'
10. Vitamin D has been linked to a reduced risk of developing autoimmune conditions including Multiple Sclerosis (MS), type 1 diabetes and rheumatoid arthritis
'Vitamin D receptors have also been found in the immune system on cells such as lymphocytes, and links have been drawn with autoimmune disease especially thyroid disease,' says Dr Macnair. 'People with other autoimmune diseases have also been found to be more likely to be Vitamin D deficient, including multiple sclerosis, auto-immune hepatitis, psoriasis and lupus.'
She explains: 'A meta-analyisis in 2015 found that those with auto-immune thyroid disease were more likely to be deficient in vitamin D, but it is not yet clear whether this deficiency plays a part in causing the disease, or is simply a result of the auto-immune process, or just a coincidental finding in someone with chronic disease. The same is true for other conditions – we just don't yet understand what the link is, and whether it has an implications for targeting the disease process.'
11. It could even help us beat cold and flu
Recent studies have shown that taking vitamin D supplements could help to combat colds, flu and lung infections.'This is not that surprising given the links that are now being made between vitamin D status and our immune function,' says Dr Derbyshire.
In a study published in the British Medical Journal last month, researchers pooled data from 11,321 people to analyse the effect of vitamin D on acute respiratory illnesses such as earache, bronchitis, pneumonia and the common cold. The study concluded that supplements can help prevent acute respiratory tract infections, particularly among those who are deficient in vitamin D.
Public Health England, however, says the infections data isn't conclusive and continues to recommend supplements for the purposes of improved bone and muscle health.
http://www.netdoctor.co.uk/healthy-living/a27743/11-things-you-need-to-know-about-vitamin-d/
03/2017
Many of us know it as the 'sunshine' vitamin that gives us strong teeth and bones.
But there's much more to it than that, which is why it's currently the vitamin on everyone's lips.
Research shows that this vital nutrient can help in a range of ways, from boosting immunity to potentially reducing the risk of a range of chronic illnesses.
Here are 11 vitamin D facts that may surprise you.
1. Many of us aren't getting enough
'Evidence from the latest UK National Diet and Nutrition Survey shows that 1 in 5 adults aged 19 to 64 years have low blood levels of vitamin D, indicating a risk of deficiency,' says Dr Emma Derbyshire, leading nutritionist and advisor to the Health Supplement Information Service.
She adds: 'As we do not seem to be getting the amounts of vitamin D that we need from dietary sources, taking a supplement could help to 'top these up' and reduce deficiency risk.'
2. We've even seen a rise in rickets
A 2014 study found that hospital admissions due to rickets (a condition, commonly caused by a lack of vitamin D, that affects bone development in children) was the highest it's been in England since the 1960s.
Dr Derbyshire says: 'This is mostly being seen amongst children who are not getting enough sunlight, or enough milk and dairy products and are physically inactive.
'Many children are also confined indoors and do not play outside as they used to, which means that they will not be getting as much vitamin D from sunlight.'
3. Sunshine and supplements are the primary sources, not diet
Vitamin D can only be found in a small number of foods. One of the main sources is oily fish such as salmon, mackerel, herring and sardines.
Dr Derbyshire explains that we tend to under-consume oily fish in the UK. 'Mean consumption of oily fish is well below the recommended one portion (140g) per week, with UK adults eating just 54–87 grams per week, so less than half of what's recommended,' she says.
At the same time, the NHS advises the general public to have 'no more than four portions' of oily fish a week - or 'a maximum of two portions' for pregnant or breastfeeding women - because of low levels of pollutants that can build up in the body.
Other dietary vitamin D sources are red meat, eggs, some breakfast cereals and some yoghurts which have been 'fortified' with the vitamin. Milk contains small amounts, but this varies during the seasons.
Overall, our daily requirement of vitamin D cannot be met through diet alone.
Geeta Sidhu-Robb, nutritional therapist, raw food chef and founder of Nosh Detox says: 'The body takes about 10 per cent of its vitamin D from food and makes the rest from sunshine and supplements.
4. Cloud cover, sunscreen and skin tone can affect the body's ability to make vitamin D
Vitamin D is known as the 'sunshine' vitamin because it's produced in the skin when exposed to the sun's rays.
Geeta Sidhu-Robb explains: 'The sun's ultraviolet B (UVB) rays interact with a protein called 7-DHC in the skin, converting it into vitamin D3, the active form of vitamin D.'
However, the sun is only strong enough in the UK for our bodies to produce vitamin D from around late March to the end of September and, even then, various factors can affect our ability to make vitamin D.
'Limited sun exposure, coupled with sunscreen use, can prevent us replenishing our vitamin D status even during the summer months,' says Dr Derbyshire.'For these reasons, it is worth topping up with a supplement, especially during the winter months, or if we have a particularly bad summer or don't go on holiday.'
People with darker skin are also advised to consider a supplement all year round, as greater levels of melanin in the skin slows down production of vitamin D.
5. It's the only vitamin supplement the government advises for everyone
The Department of Health currently advises that everyone over the age of five (including pregnant and breastfeeding women) should consider taking a daily supplement containing 10 micrograms of vitamin D, particularly between October and March.
Children aged between one and four years should have a daily 10mcg vitamin D supplement all year round, while babies under one year who are exclusively or partially breastfed should have a daily 8.5-10mcg vitamin D supplement.
Dr Derbyshire says the new guidelines 'also recognise that some groups may have a greater risk of vitamin D shortfalls, including those who rarely go outdoors, such as the frail, housebound, those living in care homes or those wearing clothes that cover up most of their bodies.' The government recommends these groups should take a supplement all year round.
If you are considering taking a supplement, you should speak to your pharmacist for more information. Fultium Daily D3 is an easy one-a-day vitamin D supplement, which is only available from your pharmacist. It has been formulated specifically to meet the Scientific Advisory Committee on Nutrition's (SACN) and Public Health England's (PHE) new recommended vitamin D guidelines.
6. Calcium needs vitamin D to be absorbed in the body
We all know that calcium is essential for building strong bones, helping to ward off osteoporosis. But, what you might not know is that vitamin D is what actually enables our bodies to absorb calcium from food.
So, even if you're getting enough calcium in your diet, it will go to waste if you haven't got sufficient levels of vitamin D.
7. It comes in two different forms
Vitamin D3 (cholecalciferol) is the form that's made by our bodies when the skin comes into contact with sunlight. It is also found in animal food sources such as red meat and oily fish.
Vitamin D2 (ergocalciferol) is the form found in vegetarian and vegan supplements and is produced by plants in response to UV light.
Vitamin D3 has been found to be better utilised and absorbed by the human body.
8. We're starting to put it in our food
Some manufacturers have started adding vitamin D to our foods. For example, M&S now fortifies all of the bread in its pre-packed sliced bread sandwiches with vitamin D. Vitamin D levels in yeast naturally increase when the yeast is exposed to UV light and the vitamin is then transferred to the bread.
Dr Derbyshire says: 'There have been some very good trials looking at vitamin D fortification, especially in bread. Further work is needed to look into which forms of vitamin D are best used (typically D3), the levels of fortification needed to have measurable benefits and the realities such as how much bread would we need to eat each day.'
9. Vitamin D deficiency has been linked to fatigue and depression
'Fatigue is a very generalised and subjective symptom linked to many other diseases,' explains Dr Patricia Macnair, specialty doctor in medicine for the elderly at The Royal Surrey County Hospital, Guildford. 'Low vitamin D levels are common among those who complain of fatigue, but science has yet to unravel whether the low vitamin D level itself plays a part, or whether the fatigue simply reflects underlying conditions. However, as with other conditions, it makes sense to check vitamin D levels and give supplements if they are low, to try to normalise the patient's physiology as far as possible. '
She adds: 'Although we think of vitamin D as a vitamin with action on the bone, we now understand that it works as a hormone on various systems in the body, and that there are vitamin D receptors in the brain. It appears to modulate neurotransmitters including dopamine and serotonin which both play a part in mood. So it makes sense to wonder if vitamin D may affect depression.
'There are a growing number of studies looking at possible links between vitamin D levels and depression, but the picture isn't very clear yet.'
10. Vitamin D has been linked to a reduced risk of developing autoimmune conditions including Multiple Sclerosis (MS), type 1 diabetes and rheumatoid arthritis
'Vitamin D receptors have also been found in the immune system on cells such as lymphocytes, and links have been drawn with autoimmune disease especially thyroid disease,' says Dr Macnair. 'People with other autoimmune diseases have also been found to be more likely to be Vitamin D deficient, including multiple sclerosis, auto-immune hepatitis, psoriasis and lupus.'
She explains: 'A meta-analyisis in 2015 found that those with auto-immune thyroid disease were more likely to be deficient in vitamin D, but it is not yet clear whether this deficiency plays a part in causing the disease, or is simply a result of the auto-immune process, or just a coincidental finding in someone with chronic disease. The same is true for other conditions – we just don't yet understand what the link is, and whether it has an implications for targeting the disease process.'
11. It could even help us beat cold and flu
Recent studies have shown that taking vitamin D supplements could help to combat colds, flu and lung infections.'This is not that surprising given the links that are now being made between vitamin D status and our immune function,' says Dr Derbyshire.
In a study published in the British Medical Journal last month, researchers pooled data from 11,321 people to analyse the effect of vitamin D on acute respiratory illnesses such as earache, bronchitis, pneumonia and the common cold. The study concluded that supplements can help prevent acute respiratory tract infections, particularly among those who are deficient in vitamin D.
Public Health England, however, says the infections data isn't conclusive and continues to recommend supplements for the purposes of improved bone and muscle health.
http://www.netdoctor.co.uk/healthy-living/a27743/11-things-you-need-to-know-about-vitamin-d/
