Vitamin D3: A New Horizon!

In 2012, the total number of studies on the benefits of vitamin D was just over 8,200. Since then (2016), these numbers have grown to over 100,000 new articles on the topic and are continuously increasing, as scientists and doctors are still working to fully understand the complex essentiality of this molecule within the human body.

Initially discovered, vitamin D was indicated for bone health, and the prevention and treatment of rickets. Currently, studies have shown broader implications in many body systems. Among others, it supports the immune system through the prevention of infections and its immunomodulatory function; strengthens the osteomuscular system; acts in the prevention of heart diseases; prevents degenerative diseases of the nervous system; and has a preventive effect against various cancers.

In Brazil, the movement for higher doses of vitamin D supplementation currently occurs on an individual basis, through health professionals who follow scientific advancements and professional organizations, such as the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM). However, it is concerning that a large segment of the population does not receive this updated information. According to the SBEM, 85% of elderly individuals in São Paulo (and 90% of institutionalized elderly) have inadequate vitamin D levels. In the healthy young adult population, the percentage is 50%. The SUS provides doses of 400 IU of the vitamin, a dose now considered insufficient to maintain adequate serum levels.

Some societies advocate for 1,000 IU/day or 7,000 IU per week as “sufficient.”

The numbers indicate that we are erring on the side of scarcity rather than excess in several aspects regarding vitamin D dosage. Some healthcare professionals fear that excessive vitamin D (which is extremely rare), for example, could cause kidney stones. This concern, at first glance, may seem reasonable, as vitamin D is involved in calcium absorption, which could increase the risk of kidney stones. This theory has what is called “apparent validity,” meaning it sounds plausible. However, two recent studies found exactly the opposite: the lower the 25(OH)D level, the higher the risk of kidney stones, partly because PTH (parathyroid hormone) in cases of hypercalciuria (excessive renal calcium excretion) is usually elevated, meaning the calcium is coming from the person's own bones.

The issue of excess needs clarification: although the vast majority of people taking D3 supplements experience no problems, the possibility of excess can occur if, erroneously, someone ingests more than 40,000 IU/day for more than 2 consecutive months, or a massive single dose if its metabolization is irregular. In clinical practice, what goes incredibly beyond the recommended: 2,000 IU to 5,000 IU/day, followed by blood measurement to achieve an ideal serum level of 50 ng/ml to 80 ng/ml.

As with any substance, excesses can become toxic, but it has been discovered that the doses of vitamin D required to become toxic are much higher than previously believed. Our body, in the best environment and with optimal nutrition, would have the capacity for ENDOGENOUS PRODUCTION of up to 20,000 IU/day.

Objective dose control is possible through an accessible blood test in any laboratory to make the necessary adjustments.

Experts advise that the vitamin D test should be included in the list of routine examinations. Blood concentration is reliable for checking your needs and has a preventive effect as important as measuring cholesterol and glucose.

This content is part of Clínica Revitalize's commitment to translating science into accessible clinical practice — without losing rigor or depth.