Vitamin D: why your levels don't increase (and it's not the dose's fault) - The Wom

Learn why vitamin D levels may be low despite taking supplements.Factors such as absorption, magnesium and weight can affect effectiveness.

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When integration doesn't work

Many patients are surprised when, after a period of supplementation, blood tests reveal that the level of 25-hydroxyvitamin D (the storage form we measure) is still below the desired level.This situation is common in clinical practice, but does not necessarily cause alarm.It is important to understand that vitamin D has slow pharmacokinetics: reaching a stable level in the blood (the so-called "plateau") requires time and consistency.The path to the normalization of blood values ​​is a biological process that depends on individual variables and does not happen immediately.

It's not just a question of underdosing, although underdosing is common.Often the problem lies in adherence to treatment or factors that affect pharmacokinetics, that is how the body absorbs, distributes and metabolizes the molecule. The analysis of these factors is necessary to make the treatment effective and to avoid increasing unnecessary doses without correcting the intake method first.

Absorption: Vehicle weight and meal

A related aspect is molecular chemistry.Vitamin D is fat soluble and requires fat (fat) for optimal absorption in the gut.Although the bioavailability of modern cream or soft capsule formulations is better compared to older dry tablets, scientific evidence suggests that absorption is significantly increased when taken with the main meal of the day, usually on an empty stomach, with the highest fat content of the supplement.

However, it is necessary to reduce the sometimes excessive emphasis on cofactors in non-specialized areas.Although a severe magnesium deficiency can theoretically interfere with the enzymes that metabolize vitamin D, in the general population with a varied diet, systematic magnesium supplementation is not strictly necessary to increase vitamin D levels, unless there is a definite deficiency of this mineral.Also, although vitamin K2 plays a role in bone metabolism, there is no solid evidence that its intake influences serum levels of vitamin D or its intestinal absorption.Therefore, if the objective is to increase vitamin D, the clinical priority remains the correct intake of cholecalciferol.

Physiological barriers: body weight and malabsorption

There are real medical conditions that hinder the achievement of the intended treatment.Importantly, supported by strong evidence, is body mass index (BMI).Vitamin D, fat-soluble, is distributed throughout the body.With weight or obesity, the phenomenon of "volumetric dilution" occurs: the vitamin is stored in fat and less in the circulation.Clinically, this means that the obese patient usually achieves the same blood pressure.An overweight person needs two to three times.

In addition, the health of the digestive system should be taken into account.Conditions such as celiac disease, chronic inflammatory bowel disease (eg, Crohn's disease), or previous bariatric surgery can cause malabsorption syndrome.In such cases, the intestine cannot absorb the vitamin sufficiently, so sometimes it is necessary to use very high doses or different drugs (for example, water-soluble or, rarely, parenteral) under the strict supervision of a specialist.Finally, some medications (eg, cortisone, antiepileptic drugs, or cholesterol medications) can speed up the breakdown or decrease absorption of vitamin D.

Practical advice for truly effective integration

To optimize therapy and correct vitamin deficiency, the approach must be systematic.The first step is compliance: the most common cause of treatment failure is missed doses.Irregular supplementation will prevent the necessary buildup in the tissues.

From a practical point of view, the strongest recommendation is to use vitamin D (especially cholecalciferol) in the main intake of the day.It is important to avoid "doing it yourself": the doctor calculates the dose based on the initial dose and, above all, on the patient's weight.and tampering with the product, rather than adding additional ingredients that do not comply with the instructions.Vitamin D is an important pleiotropic hormone: its management requires patience, consistency and an appropriate treatment plan.