Combate el invierno y apoya tu sistema inmune con vitamina D

Fight winter and support your immune system with vitamin D

Vitamin D is an essential vitamin and particularly important for our body to function optimally. It is commonly known for its function in supporting the bone system, as it plays a key role in the absorption of calcium and phosphorus. However, its other important functions include supporting the metabolic system, regulating our insulin production for optimal blood sugar balance, improving immunity (allergies, defenses, immune-based diseases), supporting cardiovascular health and regulate our mood. Despite its importance, vitamin D deficiency is, unfortunately, very common. This is mainly due to our lack of exposure to sunlight (which is our main source of vitamin D) along with low intake through diet. Other factors that further contribute to having low levels of vitamin D include age, the period of pregnancy and breastfeeding (being critical periods), dark or covered skin, the use of sunscreens, obesity and the intake of certain medications. .

Increased risk of deficiency in winter

With reduced daily exposure to sunlight and increased risk of infection during the colder months, it is essential that we work to optimize our vitamin D status to support our immune and bone systems in particular.

The minimum requirement for adequate synthesis of vitamin D is sufficient daily exposure of our skin to sunlight. Therefore, it is not surprising that a high percentage of the population presents a deficit, especially considering the geographical location of Chile and the current pandemic that has encouraged life inside homes. Therefore, it is vital that we increase our daily intake of vitamin D during these colder months to mitigate our reduced ability to produce sufficient amounts of this nutrient at this time of year.


The main forms of vitamin D are ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). We obtain the former from plant sources such as mushrooms and tofu, and the latter from mainly animal sources such as eggs, dairy products and oily fish (e.g. salmon, anchovies). When our bare skin is exposed to the sun's UVB rays of the correct wavelength, our skin converts 7-dehydrocholesterol into 25-hydroxyvitamin D (also known as calcidiol) which is ultimately metabolized by the liver and kidneys into the form active, 1, 25 dihydroxyvitamin D (also known as calcitriol).


Vitamin D deficiency is becoming more common. In Chile, the National Health Survey (ENS) 2016-2017 found that 84% of women between 15 and 49 years old have insufficient levels of this vitamin and in older adults only 13.4% achieve an acceptable level. Its deficiency is directly related to a greater risk of immunological and musculoskeletal dysfunction. Nowadays, it mainly arises due to our lack of exposure to sunlight, especially those with a sedentary indoor lifestyle (e.g. working in an office or from home) which, let's face it, is most of us this year, along with low intake through diet. The main factors that influence vitamin D deficiency are:

Winter: As we approach winter, our exposure to sunlight will be even more limited and it is important to ensure our vitamin D levels remain within optimal ranges. This is particularly important as vitamin D can improve our immune response against various common winter infections, such as influenza and upper respiratory viral infections (COVID). It also supports mental health conditions such as seasonal affective disorders (SAD) and depression, which is why vitamin D supplementation was shown to be effective in reducing depressive symptoms in SAD patients. It is suggested that vitamin D can improve serotonin production, so its effects improve mood.

Diet: Due to the Western diet and lifestyle, we find it increasingly difficult to maintain adequate levels of vitamin D in our body. Food sources of vitamin D include oily fish, such as salmon, mackerel, and sardines, eggs, and raw milk. However, due to increased fish and poultry farming, vitamin D levels in these sources are lower than expected. For example, farmed salmon was found to have about 75% less vitamin D compared to wild salmon. Therefore, a vitamin D supplement is essentially the best way to ensure we get our daily dose.

Magnesium : Magnesium is necessary to activate vitamin D, so if you are depleting it, from low dietary intake coupled with high levels of stress, this could be affecting vitamin D status.

Vitamin D is a fat-soluble vitamin, so people with digestive problems or difficulty digesting fat may not be able to absorb and metabolize vitamin D well. It is important for these people to select an emulsified (pre-digested) version. of vitamin D to ensure optimal absorption ( Nutrisorb D3 & k2 ).

Finally, there are people who have variants of the gene that encodes the vitamin D receptor (VDR), which can make it difficult for vitamin D to bind to it and then carry out its multitude of different actions within cells.

If any of the above factors are relevant to you, it is very likely that your vitamin D level is suboptimal and it would be worth increasing your vitamin D intake daily to optimize your health.


In Chile there is no standardized daily recommendation for Vitamin D. When there is a demonstrated deficiency, individuals require higher doses and are best guided by a healthcare professional. It is worth noting that a vitamin D test, obtained through your GP or privately, is the best way to find out which daily supplemental dose of vitamin D is most suitable for your needs.

In recent years, there has begun to be suggested the importance that everyone should supplement with vitamin D during the fall and winter, and throughout the year for those with limited exposure to sunlight even during the summer, such as those who cover themselves with religious reasons or people with an indoor and sedentary lifestyle, for example working in an office. When a deficiency is present, individuals will require significantly higher doses of vitamin D, given for at least 3 months and then levels will be retested.

Obese people, patients with malabsorption syndromes and patients receiving glucocorticoids, anticonvulsants may require even higher doses of vitamin D. Finally, pregnant women, breastfeeding women, nursing babies, children with allergies and older adults are groups of Take special care when we talk about vitamin D deficiency. In this sense, we would like to recommend that we get into the habit of requesting an analysis of serum vitamin D levels and thus be able to carry out adequate supplementation.

Include vitamin D as part of your winter supplement protocol this year!


Vitamin D3 (BioD)

This is a medium-strength liquid vitamin D3 option, which provides 100IU per drop, giving the option to adjust the dose in children (from one month old) and adults according to their needs (EX: 4 drops will provide 400IU and 8 drops 800IU ). This hypoallergenic liquid is designed for those looking to get started with their supplementation and offers flexible dosing options. It is perfect to share with the family, since it is suitable for all ages and has a pleasant flavor. Ideal for traveling or having in your bag for convenience since this product does not require refrigeration.

Nutrisorb D3K2

Vitamin D3 & K2 in high potency liquid format. Provides 1000IU of vitamin D3 along with 75 mcg of vitamin K2. This unique, hypoallergenic formula is especially suitable for people who have difficulty swallowing tablets or capsules, digestive and absorption difficulties and/or who require therapeutic bone and immune support. Supplied in glass bottle. Consume 6 drops per day directly under the tongue with food, or more as directed by a healthcare professional.

Nutritionist Valeria Riquelme V.

Extract translated and adapted from BioCare UK

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