According to epidemiological studies, over 90% of Poles have vitamin D deficiency. Lack of this nutrient in the diet increases the risk of, among others, diabetes, depression, multiple sclerosis, and cancer. Therefore, even healthy individuals should consider vitamin D supplementation.
Although most of us know its role in preventing rickets or osteoporosis, we still do not appreciate this substance enough. Is it worth supplementing vitamin D all year round, or only in the autumn-winter period? What are the symptoms of deficiency? Does vitamin D support immunity? All answers can be found in this article.
Vitamin D deficiencies in Poland. The deficit is huge
Although vitamin supplements are very popular, many people still overlook the most important one: vitamin D. Studies show that, not only in Poland but across Europe, vitamin D deficiency is extremely common. It is observed in all age groups. Experts warn that even 90% of Poles function with vitamin D deficiency, defined as 25(OH)D below 30 ng/ml.
This leads doctors and dietitians to increasingly recommend supplementation with this vitamin. Severe deficiencies significantly increase the risk of many serious diseases, including cardiovascular disorders, cancers, depression, and autoimmune diseases. Therefore, although vitamin D is mainly associated with preventing rickets in children or osteoporosis in adults, its impact on the body is much broader.
Valuable vitamin D: what does scientific research say?
For many years, it was known that vitamin D deficiency is associated with rickets in children and osteoporosis, fractures, and muscle weakness in seniors. With advances in science, additional properties of this nutrient have been discovered. It turns out that vitamin D actually affects the entire body—regardless of age or gender. This is because its receptors are present in almost every cell of the human body.
This is particularly important, given that vitamin D deficiency increases the risk of civilisation-related diseases. Every year, the number of people suffering from diabetes, hypertension, breast cancer, and colorectal cancer increases. Furthermore, vit. D plays an important role in the prevention of autoimmune diseases, multiple sclerosis, rheumatoid arthritis, and even depression.
Is it worth supplementing vitamin D all year round?
Many patients ask doctors whether vitamin D should be taken year-round or only in autumn and winter. The answer is clear.
The primary natural source of vitamin D is our skin. The human body synthesises this nutrient through the skin under the influence of sunlight. Unfortunately, Poland’s geographical location does not support sufficient vitamin D production. Skin synthesis occurs in our country only from the end of April to the beginning of September—and only on sunny, nearly cloudless days between 10:00 and 15:00. Another requirement is exposure of at least 18% of the skin surface (preferably legs and forearms not covered with sunscreen) for at least 15 minutes daily.
Unfortunately, when we consider that on a cloudy day, this process will not occur, we see that skin synthesis is an extremely rare phenomenon. In autumn and winter (and often spring as well), the sun’s angle also prevents sufficient production. All of this suggests that it may be worth supplementing with vitamin D year-round.
Correcting vitamin D deficiency. Skin synthesis or supplements?
People with a very fair complexion are in an even more difficult situation. In their case, regular exposure to the sun is not recommended, as it increases the risk of developing skin cancer, including melanoma.
However, problems with skin synthesis apply to almost everyone today. Many of us travel by car and spend our days indoors (even on a perfectly sunny day). Air pollution, sunscreen use, older age, and chronic diseases also contribute. As a result, both children and adults are widely exposed to vitamin D deficiency.
Some argue that vitamin D can be obtained from food, such as fatty fish, milk, or egg yolks. However, its content in food is insufficient, even negligible. Therefore, the only effective way to correct deficiencies is regular vitamin D supplementation.
What are the symptoms of vitamin D deficiency? Key symptoms
Vitamin D is included in many different supplements for a reason. It is present in supplements for energy, immunity, bone health, and cognitive function.
This is because, among other things, the numerous functions of this component in the body mean that its deficiency causes non-specific symptoms. Therefore, it can be mistaken for other conditions.
The main symptoms of vitamin D deficiency are:
- bone and joint pain,
- low mood, depression,
- reduced immunity,
- frequent infections,
- fatigue and weakness,
- increased hair loss,
- memory and concentration problems,
- difficulty falling asleep, frequent waking,
- cognitive impairment.
It is also recommended to supplement vitamin D in the prevention or treatment of certain conditions, such as osteoporosis, diabetes, dental and periodontal diseases, seasonal depression, and hyperparathyroidism.
Does vitamin D support immunity?
Vitamin D affects not only the condition of teeth, bones, and joints. In fact, it regulates calcium-phosphate metabolism. Deficiency in children leads to rickets, and in adults to osteomalacia, osteoporosis, increased fracture risk, muscle weakness, and bone pain of varying intensity.
However, vitamin D also affects the immune system. It has strong immunomodulatory effects. It interacts with VDR receptors present in immune cells (especially T and B lymphocytes, macrophages, and dendritic cells). It is involved in:
- inhibition of excessive pro-inflammatory cytokine expression,
- stimulation of antimicrobial protein production (in T and B lymphocytes, monocytes),
- stimulation of interferon activity,
- promotion of anti-inflammatory cytokine production.
Therefore, does vitamin D help with immunity? Definitely yes. It actively stimulates the immune system, protecting against disease and infections.
Vitamin D in immunity-boosting preparations
It is no surprise that high-quality immune supplements often contain this valuable ingredient. It is used both in multivitamin formulas and as standalone products, e.g., vitamin D drops.
A vitamin D supplement is intended to support:
- strengthening the immune system,
- improving mood and well-being,
- enhancing memory and concentration,
- preventing the development of many diseases,
- protecting against hypertension and civilisation diseases.
Learn the principles of proper vitamin D supplementation
Over-the-counter vitamin D supplements come in various doses. They also come in different forms. Pharmacies offer drops, capsules, tablets, and even sprays.
- According to general guidelines, adults should take 2000–4000 IU/day. For seniors over 75, the recommended dose is 3000–6000 IU/day depending on blood levels. When using higher doses, it is recommended to increase magnesium intake (e.g. BestMag) and vitamin K2 MK7 (e.g. in BestOne).
It is worth remembering that vitamin D is fat-soluble. That's why so many products come in oil-based forms. This is no different for the BestLab preparation, i.e., Best Vitamin D3, whose specially designed formula is enriched with natural coconut MCT oil. Thanks to this, the preparation ensures proper absorption of vitamin D.
What dose of vitamin D for children?
Vitamin D supplementation in children is essential, particularly given the risk of rickets and growth disorders. In that case, what dose of vitamin D for children will be appropriate?
- Children aged 1-3 years - for healthy children in this age group, daily supplementation at a dose of 1000 IU/day is recommended throughout the year.
- Children aged 4-10 years - for healthy children in this age group, daily, year-round supplementation at a dose of 2000 IU/day is recommended (depending on body weight and vitamin D intake in the diet).
- Adolescents aged 11-18 years - for healthy adolescents of this age, daily, year-round vitamin D supplementation at a dose of 2000-4000 IU/day will be indicated (depending on body weight and intake of this ingredient with the diet).
It is worth remembering that in addition to single-ingredient drops or capsules with vitamin D, there are also multi-ingredient preparations with the addition of this substance, such as BestForKids - a supplement supporting the daily diet in building well-being and immunity in the youngest.
Vitamin D dosage for infants
Sun exposure is not recommended for children until they are 3 years of age. The safest option is therefore oral administration of vitamin D to the child as drops or a spray. Vitamin D dosage for infants:
- 0-6 months of age: 400 IU/day, regardless of whether the child is breastfed or formula-fed;
- 6-12 months of age: 400-600 IU/day.
Supplementation should be monitored by measuring serum vitamin D levels during the infant's hospital stay and in outpatient care.
Later, parents continue to administer vitamin D at home. For newborns, there are special sprays, drops such as Best Vitamin D3, or twist-off capsules available, which are administered directly into the child's mouth or food. Drops, in particular, are characterised by their ease and convenience of use – the amount of vitamin administered can be easily adjusted to the body's needs, and the liquid form means that swallowing the supplement is not a problem even for babies who are not yet taking solid foods. This is why the vast majority of parents choose vitamin D in drops.
Sources:
- Rusińska A, Płudowski P, Walczak M i wsp.: Zasady suplementacji i leczenia witaminą D – nowelizacja 2018 r. Standardy Medyczne – Pediatria 2018; 15: 531-559.
- Kmieć P, Sworczak K. Korzyści i zagrożenia wynikające z suplementacji witaminą D. Forum Medycyny Rodzinnej 2017; 11(1): 38–46.
- Holick M.F., Chen T.C. Vitamin D deficiency: a worldwide problem with health consequences. Am J Clin Nutr 2008; 87 (9 Suppl): 1080S–1086S.
- Kurowska K, Antosik K, Decyk A i Kobylińska M. Znaczenie witaminy D w zapobieganiu i leczeniu depresji. Medycyna Ogólna i Nauki o Zdrowiu 2021; 27(2): 121-125
- Muscogiuri G, Tirabassi G, Bizzaro G i wsp.: Vitamin D and Thyroid Disease: to D or not to D? European Journal of Clinical Nutrition 2015; 69(3): 291-296.
- Quraishi S.A., Camargo C.A., Manson J.E. Low vitamin D status in Europe: moving from evidence to sound of public health policies. Am J Clin Nutr 2016; 103: 957–958.
- https://naukawpolsce.pl/aktualnosci/news%2C399291%2Cekspert-ponad-90-proc-polakow-ma-niedobory-witaminy-d.html
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