Focus on the vitamin effectiveness data in light of current scientific evidences
Focus on vitamin D: effectiveness data in light of current scientific evidences
A real focus published in Nutrients (*) for the correct approach to the treatment of Vitamin D deficiency, developed by a group of experts from AME, the Association of Endocrinologists.
“The publication places itself as a reference for the scientific community that confronts this rather frequent condition even in our country considered the country of the sun”, introduces Vincenzo Toscano, president of Ame. “In recent years vitamin D has been the center of attention and as endocrinologists we felt the need to find answers to questions such as: vitamin D is really a panacea? Protects from diabetes and cancer?
Doctors must focus their attention on circulating levels throughout the population in an important way? The preparations of vitamin D are all the same? The doctor can choose any vitamin D preparation and administer it equivalently?
Focus on vitamin D
The Endocrinologists Association through its experts has clarified these topics by publishing ad hoc guidelines by highlighting what is reported in literature in the methodological perspective of medicine based on the evidence that has always characterized the activity of the exam “.
Vitamin D performs important functions for bone health by helping the body to absorb calcium, one of the main constituents of our skeleton and preventing the onset of bone diseases, such as osteoporosis or rickets. Any Vitamin D deficiency is evaluated through a blood dosage, which is thus interpreted, with some variations according to the different laboratories and above all according to the dictates of the different medical societies: deficiency <10 ng/mL; insufficient: 10 – 30 ng/mL; sufficiency: 30 – 100 ng/mL; toxicity: >100 ng/mL.
Roberto Cesareo, endocrinologist, S.m. Goretti
“The values of Vitamin D”, explains Roberto Cesareo, endocrinologist, S.m. Goretti, Latina and first signatory of the work, “currently adopted, therefore provide that subjects with a value lower than 30 ng/dl can be declared affected by Vitamin D insufficiency. In our opinion, this limit should be re -evaluated as it is too high, especially in the absence of strong scientific evidence.
The adoption of these levels constitutes one of the reasons why you end up declaring “lack of vitamin D” so many subjects who are probably not. In the consensus we considered more appropriate to define the vitamin D values reduced when they are clearly below 20 ng/dl. This difference seems to be apparently trivial, but a good part of the declared subjects “lacking in vitamin D” fall precisely in this scissor that goes between 20 and 30 ng/dl thus involving, as is actually verified, an incongruous prescription of this molecule.
Conversely, osteoporotic subjects or patients who are already taking drugs for the treatment of osteoporosis or other categories of subjects significantly more at risk of vitamin D deficiency, it is correct, in our opinion, that they have Vitamin D values higher than the limit of 30 ng/ dl and therefore they must be treated”.
“We then tried to clarify”, continues the expert, “that, at the moment, although there is an incontrovertible series of data that associate Vitamin D deficiency with other diseases that are not just osteomalacia and osteoporosis (see diabetes mellitus, some neurological syndromes, some types of tumours), it is not known which are the correct dosages of Vitamin D that may be useful for reducing the incidence of these related pathologies. We believe it is right to report this data as passing on the message that Vitamin D is the elixir of life, as well as incorrect in that it lacks strong scientific evidence, risks being subject to incongruous over-prescribing and with the risk of taking this molecule without real benefits”.
Fabio Vescini, SOC Endocrinology and Metabolic Diseases
“However, it should be remembered”, adds Fabio Vescini, SOC Endocrinology and Metabolic Diseases, Santa Maria della Misericordia University Hospital, Udine “that the prevention of hypovitaminosis D passes through a correct lifestyle, that is, a correct lifestyle. adequate exposure to sunlight and a balanced diet. It should be emphasized, however, that with the aging of the efficiency of the biosynthetic skin mechanisms tends to reduce themselves and therefore it is more difficult for the elderly people to produce adequate quantities of vitamin D with the exposure to sunlight. Therefore, in patients with osteomalacia or osteoporosis, in the elderly especially those most exposed to falls, in subjects who by force of things cannot expose themselves adequately to sunlight, the treatment with the integration of vitamin D must be considered.
A valid alternative could be the policies of “ fortification ” foods with vitamin D, as happens in the countries of the Scandinavian area, where solar radiation is naturally less rich in UVB rays.
It is good to know that sunlight also in our country “defined the country of the sun” for long periods of the year (autumn-winter) does not contain a UVB radiation sufficient to make vitamin D produce in the skin; Paradoxically, this can also occur in summer, as the appropriate application of creams with sunscreen reduces the penetration of sunlight in the skin and, consequently, the biosynthesis of vitamin D. Seasonal variability in plasma Vitamin D values is reported in the literature. In fact, they tend to be maximum in autumn and reach a nadir in late spring. There is no “recommendation” about the best period in which to perform the dosage of plasma Vitamin D. Certainly a low value, detected in the autumn, is a sign that Vitamin D stocks were not replenished in the summer that has just passed and it is logical to expect that this patient will have severe hypovitaminosis D in the spring”.
“Furthermore”, continues Cesareo, “it is necessary to know that Vitamin D molecules are not all the same. The inactive form, the one most commonly used, is cholecalciferol. This molecule usually prescribed in the form of drops or vials to be taken either daily or once a week or on a longer term basis (monthly or even bimonthly) is subsequently activated first in the liver and then in the kidneys and, as such, carries out its finalized effects in particular to a correct absorption of calcium in the intestine and to a control of the phospho-calcium metabolism in the bones. But there are other molecules that are already partially or fully active.
Among them, calcifediol deserves attention, which does not need to be activated at the level of the liver and due to its molecular characteristics is, as they say in jargon, less “fat soluble”, i.e. it remains less in the adipose tissue than the previous molecule mentioned, cholecalciferol. Both of these molecules do not cause problems, in particular alteration of calcium levels in the blood and/or urine, if prescribed appropriately and in correct doses. Due to its kinetics of action and its conformation, calcifediol can find a reason for greater use, as mentioned, in patients who have liver pathologies of a certain importance and also in obese and Vitamin D deficient subjects or in those who are affected from intestinal malabsorption problems.
It too is prescribed in drops or soft capsules in daily, weekly or monthly prescriptions. The cholecalciferol, on the other hand, finds its main indication in subjects suffering from osteoporosis and/or which simultaneously take drugs for the treatment of this pathology “.
“Finally”, concludes the expert, “the completely active metabolites and that therefore do not require liver or renal activation find a much more limited field of use, in particular in subjects suffering from renal failure or who are lacking in the hormone Parathyroid, clinical picture that is usually found in the work of thyroid and wallpaper. Their reduced use in the patient with simple vitamin D deficiency is dictated by the fact that, compared to the two molecules described above, they expose the patient to a greater risk of hypercalcemia and increased levels of calcium in the urine “.
