November arrives, and with it, shorter days and fewer hours of sunshine. It is already night, plus warm clothing when leaving work or school.
It is “a non-soluble vitamin,” according to the Nutrition and Dietetics Specialist and Team Leader of the Clinical Nutrition and Dietetics Unit of the Quirón Salud Hospital in Valencia.
It is also involved in the defense against infections and the modulation of the immune response, according to an expert in orthomolecular nutrition, diabetes, obesity, metabolism, and eating disorders (ED), because it avoids hypersensitivity by T lymphocytes, which is critical in autoimmune diseases. It also helps prevent inflammatory and cardiovascular diseases and some types of cancer such as breast and prostate.
Active vitamin D acts as a hormone and is involved in modifying and repairing genetic material and regulating the cardiovascular system. It also intervenes in insulin secretion through calcitriol (an active vitamin D3 that increases calcium absorption at the intestinal level, bone mineralization, and its reabsorption at the renal level).
It can prevent mental disorders because those responsible for activating this substance are found in the brain.
at risk of deficiency
- Breastfed babies, because human milk is not a good source of vitamin D
- Older because their skin does not produce the same amount of this substance when sunbathing.
- People with dark skin as they have less capacity to make it.
- Those with Crohn’s disease or celiac disease do not absorb fat correctly, and this vitamin needs to be assimilated.
- People with obesity, because their body fat prevents this vitamin from entering the blood
- Individuals with gastric bypass, osteoporosis, chronic kidney or liver disease, and hyperparathyroidism
- Those suffering from sarcoidosis, tuberculosis, histoplasmosis, or some types of lymphomas
- People taking cholestyramine, anticonvulsants, glucocorticoids, antifungals, or other anti-HIV drugs
There is talk of vitamin D deficiency –explains Bosh– when its values are below 20 and 30 ng/ml.
The difficulty is that our bodies would then have to draw on their calcium reserves, which is a mineral that must be sustained at constant levels because its depletion might result in death.
The deficit of this substance also leads to demineralization, that is, osteoporosis and the risk of fractures in adults and rickets in children.
The most critical months to reach the recommended doses of this vitamin are from November to February. Bosh explains that even though in spring and summer, it is enough to sunbathe 10 minutes a day, during this time, we should extend this exposure to 30 minutes.
This is important because, through sun exposure, we absorb 80-90%. Gimeno recalls that sunscreen significantly reduces the production of said substance. With food, we can get between 10-20%, which can be of great help in autumn and winter, although it is a low percentage.
Foods rich in vitamin D
- Yolk
- Blue fish: anchovies, boquerón, sardines, salmon, tuna, mackerel, bonito, sea bream…
- Seafood: prawns, prawns, clams, oysters.
- non-skimmed dairy
- Butter
- Offal: veal and rabbit liver
- mushrooms
The recommended amount of vitamin D varies according to age and ranges from 400 IU (International Unit) in babies under one year of age to 800 IU in older people. Another way to obtain this substance, in the case of a deficiency, would be through nutritional supplements, always consulting previously with our doctor.