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How long does it take for vitamin D spray to work?

If you are one of the many people who have difficulty swallowing tablets and capsules, then you may do better with a vitamin D oral spray. 

How many people have difficulty swallowing pills?

Surveys in general practice suggest that more than one in three people (37%) experience problems taking prescribed pills. As a result, most medicines are available in different formulations, such as liquid syrups and, in some cases, oral sprays.

How effective are vitamin D oral sprays?

Many nutrients and medicines are readily absorbed via the mouth lining, and technology has progressed to allow the development of oral sprays, which are becoming increasingly popular.

A recent study compared the effectiveness of a vitamin D oral spray against vitamin D capsules in maintaining blood levels of this important nutrient during winter, when the level of UV sunshine is too low to synthesise vitamin D in the skin.

The type of vitamin D used in this study was vitamin D3, which is more effective at maintaining blood vitamin D levels than the plant form known as vitamin D2.

A group of 22 healthy volunteers in Ireland received 3000 IU (75 µg) vitamin D3 every day for 4 weeks, in either capsule or oral spray form. Then, after a 10-week 'washout' period, they switched to taking the other formulation for another 4 weeks. This allowed comparisons to be made between the vitamin D3 spray and the vitamin D3 capsules for each volunteer. This study confirmed that in healthy adults living in a northerly latitude (55°N), that taking vitamin D3 in the form of an oral spray was equally effective at raising blood vitamin D concentrations as taking it in capsule form. The researchers stated that the use of a vitamin D3 oral spray was a suitable alternative to capsules for the general population, if desired.1

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How soon does a vitamin D spray start to work?

A vitamin D3 spray will start to work straight away in raising blood vitamin D levels. The inside of the mouth has a rich blood supply which is why it appears so red. After spraying vitamin D3 into the mouth, it is absorbed across the thin layer of cells lining the cheeks and under the tongue, directly into the tiny blood capillaries beneath.

Once in the blood stream, the vitamin D obtained via an oral spray is treated exactly like the vitamin D that is made in the skin, or absorbed from tablets via the gut. Within the circulation, the absorbed vitamin D is captured by special binding proteins that transfer it to the liver where it undergoes its first activation - a process known as hydroxylation. This partially active vitamin D is then further activated by other body cells, especially those in the kidneys, to form the fully active form of vitamin D (calcitriol).

The active form of vitamin D is produced within minutes of using an oral vitamin D spray. The activated form can then start interacting with vitamin D receptors to perform its beneficial tasks relating to calcium and phosphorus absorption, immunity and regulation of mood.

How much vitamin D do you need?

The National Institute for Health and Care Excellence (NICE) recommends that all adults in the UK take a daily supplement containing 400IU (10mcg) of vitamin D all year round. Many experts recommend higher intakes of at least 25mcg per day.2

Who should use a vitamin D spray?

Anyone can use a vitamin D spray in preference to tablets or capsules if they wish. A spray is particularly helpful for those who have trouble swallowing pills. It's good to have a choice of vitamin delivery methods, as everyone is different and has different requirements.

Dr Sarah Brewer is Healthspan's Medical Director and holds degrees in Natural Sciences, Surgery and Medicine from the University of Cambridge. Having worked as a GP and hospital doctor, Dr Sarah now holds an MSc in Nutritional Medicine from the University of Surrey and specialises in nutrition. She is also an award-winning writer and author.

Find out more at Dr. Sarah Brewer's website, or read more about Healthspan's health experts.

Nothing beats a healthy, balanced diet to provide all the nutrients we need. But when this isn't possible, supplements can help. This article isn't intended to replace medical advice. Please consult your healthcare professional before trying supplements or herbal medicines.