The prevalence of vitamin D deficiency is high, and most patients require vitamin supplementation, since they do not usually meet their daily needs through skin synthesis and diet.
Causes of vitamin D deficiency
The main cause of this deficit is the lack of sun exposure. However, low vitamin D intake can also contribute to this deficit, although it is not determinant since 90% comes from skin synthesis. Recent publications consider that these causes would only explain one quarter of the individual variability in vitamin D concentrations and the remainder would be attributable to genetic factors. Obese patients are predisposed to deficiency, since there is sequestration of vitamin D in body fat. Therefore, it decreases bioavailability, as well as hepatic hydroxylation and due to the inflammatory state associated with central or visceral obesity.
Treatment of disability
If the concentration is insufficient, between 20-29 ng/ml, there are authors who consider that it may be sufficient to administer a dose of 800-1,000 IU daily. However, in the elderly (> 70 years) higher doses, close to 2,000 IU/day are necessary.
If vitamin D concentrations are in the deficiency range, between 10 and 19 ng/ml, 16,000 IU is administered weekly. If serum values are 20 < ng/mL, the dose should be repeated for 10 weeks or more. So as a maintenance dose, 16,000 IU every 2-4 weeks. If vitamin D concentrations are below 10 ng/ml, severe deficiency is considered. Since, there may be osteomalacia when concentrations <are 10-12 ng/ml, then more aggressive treatment is required, since the risk of falls and fractures is more pronounced. It is usually effective to administer a shock dose of 25-OH-D3 of 180,000 IU followed by an over 16,000 IU per week, although we should evaluate the concentrations one month after administration and act depending on the serum values achieved.
There are special situations that require a different treatment regimen. In obese patients with malabsorption syndrome or using drugs that increase vitamin D catabolism, 2 to 3 times more vitamin D can be administered, 6,000-10,000 IU/day, followed by 3,000 to 6,000 IU/day of maintenance. Finally, if it is decided to administer vitamin D weekly, it is necessary to give 16,000 IU of 25-OH-D3 for 8-12 weeks if concentrations above 30 ng/ml are not reached.
Study suggestion: Importance
of prophylactic vitamin D in childhood
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: Vitamin D far beyond a vitamin
Vitamin D deficiency
– Aguilar del Rey FJ. Protocol de tratamiento de la deficiencia de vitamin D [Protocol of treatment of vitamin D deficiency]. Clin Med (Barc). 2014;142(3):125-131. doi:10.1016/j.medcli.2013.06.012