MADRID, Nov. 6 (DEDIZIONES) –

Vitamin D is key for bone health, the immune system, and even your mood. Did you know? The problem is that it tends to decrease in the cold months of the year because the sun – its main source – is not enough in countries like Spain. This deficiency can promote osteoporosis, fractures and even increase vulnerability to infections. Is it always advisable to supplement or only in risk groups?

We chatted for this Europa Press Salud Infosalus report with Amalia Paniagua, who is Associate Head of the Endocrinology and Nutrition Service at the Fundación Jiménez Díaz University Hospital in Madridwho emphasizes that at this time of year, when the cold returns, although the diet is also a source of vitamin D, it is the minority, with the main source of this vitamin being the cutaneous synthesis after exposure to ultraviolet radiation.

“In latitudes above *40, such as Spain, UVB radiation is not sufficient for the cutaneous synthesis of vitamin D during the months from autumn to spring included. Factors such as age, dark skin phototype, the use of clothing that covers the skin (e.g. Islamic), obesity, and working indoors, or institutionalization (e.g. nursing homes) aggravate this seasonal decline,” says this expert.

SOURCES OF VITAMIN D IN THE DIET

Here Paniagua reminds us that dietary sources of vitamin D would include: fatty or blue fish, eggs, liver, and fortified foods, such as yogurt, milk, or butter/margarine where supplementation is indicated.

“These foods are also rich in calcium, such as nuts, apricots, figs, and broccoli.; all of them very important, along with foods rich in vitamin D for musculoskeletal health. Fortified dairy products can provide between 60-200 IU per serving. Its intake, however, is usually insufficient to maintain adequate levels without sun exposure, and in Europe it is not systematically fortified as in the United States,” he warns.

BE CAREFUL IF WE DO NOT HAVE ENOUGH VITAMIN D

Regarding the consequences that a vitamin D deficiency can have on health, Dr. Amalia Paniagua highlights that the most established health effects are musculoskeletal, that is, those that occur in bone health: “Levels <20 ng/mL can cause osteomalacia (condition that alters the bone matrix or “rickets” and muscle weakness with a tendency to instability and pain or “atromyalgia”); in addition to osteoporosis; and an increased risk of fractures.

On the other hand, it points out that there are certain indications that the deficiency (figures <25 nmol/L) may be associated with a greater tendency to respiratory infections and autoimmunity, as well as other chronic diseases, such as prediabetes, where the risk of progression to diabetes increases.

“Its relationship with mood, depression, or fatigue has also been debated, but large studies do not demonstrate robust benefit from supplementation in the general population. At the moment, Extraskeletal benefits of supplementation continue to be debated“clarifies this specialist from the Jiménez Díaz Foundation.

SHOULD WE ALL SUPPLEMENT?

So, should we all take vitamin D supplements in the cold months of the year? The associate head of the Endocrinology and Nutrition Service at the Fundación Jiménez Díaz University Hospital in Madrid explains that the main guidelines, such as those of the National Academy of Medicine and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO), recommend supplementation mainly for groups at risk of this deficiency, and not in a generalized way.

So, This expert specifies that the candidates would be: adults over 75 years of age, institutionalized people, individuals with dark skin, pregnant women, lactating women, those who avoid sun exposure, patients with digestive diseases that affect the absorption of calcium or vitamin D (e.g. celiac disease, bariatric surgery, “short intestines”), and those taking certain drugs that affect their absorption (corticosteroids, antiretovirals, cholestyramine or cholestiol, orlistat, some statins, laxatives, etc…).

Is it advisable to have an analysis before starting to take vitamin D supplements? We asked this expert, emphasizing that before starting supplementation it is advisable to measure 25-hydroxyvitamin D to calculate the necessary dose of supplementation in people with risk factors, musculoskeletal symptoms, or a history of deficiency. “In healthy adults without these factors, preventive supplementation in autumn-winter does not require prior analysis,” he says.

PRECAUTIONS TO TAKE INTO ACCOUNT WITH SUPPLEMENTATION

With all this, Dr. Paniagua maintains that the overdose of vitamin D can be harmfulcausing hypercalcemia and renal toxicity, with reduced filtration and the possible appearance of lithiasis (kidney stones).

In turn, it mentions that there are important variations in this risk depending on the type of supplementation, so in the Spanish case we use calcifediol (25-hydroxyvitamin D) and pure vitamin D (cholecalciferol).

“The use of calcifediol, despite being so widespread, It carries a greater risk of toxicity than cholecalciferol (and less efficacy). The recommended doses of cholecalciferol (<2,000 IU/day) are safe, so they can even obviate control analyzes in most patients. However, it is recommended to avoid doses greater than 4000 IU/day without medical supervision, although toxicity is rare, requiring a sustained intake of >10,000 IU/day for months. Nowadays, the previously called shock doses are clearly contraindicated,” notes this specialist.