How much vitamin D do you need and are you getting enough?

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  • As we edge more into winter this year, concerns about being unwell are skyrocketing perhaps quicker than in any other year. But instead of looking to the latest trends to stay healthy, a new study has suggested that turning back to traditional ways to fight off colds and flu could be the answer – namely, it’s vitamin D that has come to the rescue once again.

    A new study in BMJ Nutrition Prevention and Health, conducted by a team from NNEdPro Global Centre for Nutrition & Health in Cambridge and Imperial College London, has analysed data from over 600 adults to look at whether certain vitamins reduce the risk of respiratory infections. It was found that those taking supplements containing vitamin A and D were significantly less likely to report respiratory issues.

    Following this, the study’s lead authors have concluded that vitamin D supplements are “critical” in ensuring that people maintain a good level of vitamin D in their diets, as there won’t be enough through food alone. Additionally, Shane McAuliffe from the NNEdPro Nutrition and Covid-19 Taskforce has said that due to the low cost and widespread availability of vitamins, they are a “sensible” solution to solving deficiency during the winter months.

    Known as immunity nutrients, vitamins A, C and D have been hailed as wellness essentials for years, with various studies emphasising their benefits for our immune systems. But in the age of Covid-19, we need to be more careful than ever. There’s currently not enough studies to suggest that vitamin D could fight off the virus but experts widely agree that avoiding deficiency is worthwhile for the potential it has in lowering the risk of coronavirus.

    So now we’re in the colder months, when it’s difficult to know the difference between coronavirus and the flu or the common cold, it’s more important than ever to make sure that everyone knows how much vitamin D they need and whether they are getting enough. So if you can’t get your hands on a flu jab near you, here’s what the experts have to say about vitamin D…

    How much vitamin D should I take per day?

    woman taking vitamin d tablet

    Credit: Getty

    According to Harvard Nutrition Source, we should all be aiming for the Recommended Dietary Allowance of vitamin D. For adults aged over 19 years old, this is 600 IU (international unit) daily and for adults over the age of 70, it’s 800 IU daily. But the maximum daily intake unlike to cause “harmful effects on the health” is 4000 IU, so those lacking in the essential nutrient might consider topping up with vitamins matching this level.

    To put this into context, the average IU of standard vitamin D tablets is 1000 IU. This means that whatever the personal recommendation for intake of vitamin D is, a standard vitamin D tablet such as that bought in the supermarket or health food shop, should do the job.

    It’s not only for immune support that experts recommend vitamin D, however. “Vitamin D plays a vital role in calcium absorption and is required for healthy bone and cartilage development and maintenance. It can also help support healthy muscle function and circulation too.” LloydsPharmacy pharmacist, Pareena Patel tells us. “It’s a vitamin which is essential for babies, children, adults and the elderly alike. It is important to take a supplement which has the right intake for the individual. For example, babies should not be taking the same supplement as adults and vice-versa, as too much vitamin D can have a detrimental effect.”

    Are there any side effects?

    There are few side effects to worry about, especially if you’re only taking the recommended daily allowance. However, if you take too many supplements then something called vitamin D toxicity or hypervitaminosis D can occur. If this happens, then the main consequence is a build-up of calcium in the blood (also known as hypercalcemia) which can cause vomiting and nausea, muscle weakness and frequent urination. The toxicity would also escalate if it’s not dealt with and create issues in the bones and kidneys, such as the creation of calcium stones.

    For this to happen, however, there would need to be a daily intake of about 60,000 IU over several months. This is 100 times higher than the recommended daily allowance of 600 to 800 IU per day so it would be quite hard to achieve by accident. Vitamin intake via the sun or foods doesn’t contribute to this, as the body regulates any naturally occurring vitamins coming into the body.

    When should you take vitamin D, morning or night?

    woman eating breakfast high in vitamin D

    Credit: Getty

    There is limited research on whether taking vitamin D in the morning or at night is better, so it’s really up to personal preference. Some people find taking vitamin D in the morning or at a certain time of day useful for remembering, especially if they also take other tablets. Whereas others prefer the evenings at dinner time, with some research suggesting better absorption with a meal, but other minimal evidence would suggest that late-night consumption could affect sleep.

    Konstantin Karuzin, co-founder and medical director at Bioniq, tells GoodtoKnow that ultimately aiming for breakfast could be best. “Breakfast is a great time to take an immune supporting supplement, such as bioniq IMMUNE, which contains the highest-grade antioxidants and Swiss manufactured vitamins, including Zinc, Vitamin D3, K2 and C. It is blended into tiny granules that should be taken in the morning and then again in the evening for optimal absorption. This unique absorption process allows you to digest and tolerate the granules easier than vitamins that are taken singularly in pill format, which can often cause nausea and other adverse side effects. Simply mix the formula into smoothies, on top of yogurt or with juice or water.

    And to help things along, Konstantin says to aim for a well-balanced breakfast with a mixture of protein, complex carbohydrates, fats, fruits and veggies for enough energy throughout the day. “Our immune system requires energy to function optimally, and low energy intake can slow our immune system responses. Some well-balanced breakfast examples include rye bread topped with salmon and avocado, an omelette with butternut squash and yogurt topped with oats and nuts.”

    What happens when your vitamin D is low?

    When vitamin D levels are low, there are some noticeable changes in the body, says Konstantin. “Low vitamin D levels can lead to decreased energy levels, low mood, and potentially frequent bouts of illness. Checking for nutritional deficiencies can rule out any underlying issues that might be causing your lowered energy levels or even exhaustion and allow you to supplement based on what your body requires.”

    How long does it take to correct a vitamin D deficiency?

    To correct a deficiency, the Endocrine Society suggests that the deficient person has 50,000 IU of vitamin D3 once a week for eight weeks or alternatively, 6000 IU of vitamin D3 daily. This will increase the level of vitamin D3 in the blood, which should correct the deficiency.

    Uta Boellinger, from nutritional coach Aiverley, agrees with this. She says that it depends how low your levels are to start with, “Most commonly a higher dose is required for six to eight weeks.”

    So it’s fairly easy to correct with suitable intervention and it’s a good job too, since lacking in vitamin D is very common and in fact, it’s estimated that 1 billion people around the world are vitamin D deficient. This means, also, that it takes more than sunshine and nutrient-rich food to correct a vitamin deficiency so check out these supplements to get started. If in doubt, however, and you feel that a vitamin D deficiency is seriously affecting your life then the best thing to do is to make an appointment with your GP. They will be able to assess the personal situation and run tests to ensure this is actually what the problem is, as some of the symptoms of vitamin D deficiency are also that of more serious conditions.

    How can you boost intake?

    woman jogging in sunshine, known to create vitamin d

    Credit: Getty

    While classic ideas around vitamin D revolve around the sun, Konstantin says that simply having a couple of hours in the sunshine won’t be enough to create a good level of the essential vitamin in the body. “Nature has come up with a complex mechanism: to produce this micro-element, a person should not only be in direct sunlight from 11 am until 2 pm without any UV protection on the skin, but also needs to be physically active for several hours. When this vitamin is being developed in the skin under ultraviolet radiation, it needs to enter the bloodstream. This is only possible when exercising. If we just lie on the beach and sunbathe, vitamin D is also produced, but then it is instantly destroyed, without bringing any benefit to our body.”

    This means that the vitamin, as the NNEdPro Global Centre for Nutrition & Health study suggests, needs to come from other sources. Pareena Patel, Lloyds Pharmacy pharmacist, says that vitamin D tablets should offer the extra boost and shiitake mushrooms are particularly good for increasing vitamin D and lentinan (known to possibly increase quality of life and survival time for some cancer patients) levels in the body. While Uta suggests that, “Oily fish (salmon, mackerel, sardines etc) is the only true rich source of vitamin D. Liver, eggs and butter provide small amounts.”

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    Who’s likely to be lacking in vitamin D?

    While anyone can suffer with a vitamin D deficiency, according to one study, there are some who are more at risk than others due to lifestyle, culture, age and many other factors. For example, one study conducted in Iran found that women were more likely to be deficient in vitamin D than men because of the clothing they wear. Similarly, those in built-up cities tend to suffer more as the infrastructure limits the amount of sun that passes through the population.

    Others known to lack in the essential nutrient include those over the age of 70, people who spend large amounts of time inside and those who avoid foods high in the essential vitamin, such as fish, eggs, mushrooms and some types of dairy.