Vitamin D: to take or not to take?
On June 3, an updated guideline on vitamin D was published on the website of the respected Endocrine Society, which is a document that doctors refer to when making clinical decisions.
Instantly riding the wave of D-hype, doctors of various specialties (and not just doctors!) began to publicly rejoice: "See! We told you! You don't need to address these deficiencies; now we have proof!"
Is the era of vitamin D over? Or...?
In the best traditions of a pedantic practitioner, endocrinologist Anna Ustyuzhanina reread and reinterpreted the guideline.
Let's figure out how good this updated "working tool" is and what has changed in the last 13 years since the previous recommendations were published.
In brief: what you need to know
Clinical studies have not established an optimal level of 25(OH)D. Therefore, routine testing for its blood level is unnecessary (i.e., without indications).
Healthy adults aged 19 to 74 do not need to take vitamin D. (However, there is a basic recommendation to obtain 600 IU/day from somewhere, haha).
Apparently, one would need to eat 100 grams of trout daily or drink 2 liters of vitamin-enriched milk or orange juice, which are unlikely to be found on the shelves of "Pyaterochka."
Empirical (i.e., without prior laboratory determination) intake of vitamin D is recommended for:
- Children aged 1 to 18 years (to prevent rickets and potentially reduce the risk of respiratory infections)
- Elderly people over 75 years old (to reduce mortality risk)
- Pregnant women (to reduce pregnancy and childbirth complications)
- And (surprisingly!) people with prediabetes.
Why is everyone discussing vitamin D?
In hopes of curing all known and unknown ailments—from autoimmune to infectious and oncological diseases—scientists have tried to find their connection with vitamin D deficiency or insufficient intake. Unfortunately, over ten years, clear correlations and answers have not been found.
As a result, updates have followed, with the main message today being that everyone does not need to take preventive doses of vitamin D to address its so-called deficiency because it is unlikely to benefit health. Additionally, it remains unclear what should be considered normal.
Previously, we considered it to be 30 ng/mL and aimed for that; now it's unclear if there's any sacred meaning in that. However, we have already seen that prolonged intake of mega-doses of vitamin D is dangerous and leads to intoxication.
Has this become something new? Not really; back in 2011, we were advised to measure vitamin D levels only in at-risk individuals, and there has never been a directive to prescribe vitamin D to the entire population).
However, there is a caveat: in small print throughout the guideline, authors state that everyone should receive the infamous 600-800 IU of vitamin daily (where from: food or supplements is another question). To be fair: food does not contain much vitamin D, and to cover a deficiency one would have to eat 85-100 grams of salmon or other fatty fish daily. Can we handle such a task? I don't think so.
The guidelines do not suggest specific dosages since the committee could not find supporting evidence; according to Pittas:
"We do not know what it is like if we knew what an optimal dose of vitamin D was because in clinical trials we referred to for evidence there exists too wide a range of supplement doses. Further research is needed to determine the most appropriate doses for specific population groups and conditions."
But if we dig deeper, some numbers can indeed be found in this document, which is positioned as working:
- For children - recommended around 1200 IU/day (on average).
- For elderly - daily intake of 800 IU/day.
- For pregnant women - on average, they need 2500 IU/day.
- For people with prediabetes - about 3500 IU/day.
At the same time for everyone:
The recommended daily allowance for vitamin D for people aged 1 to 70 is set at 600 IU/day.
Adults aged 50 and older who have indications for treatment with vitamin D are advised to take low doses daily instead of high doses weekly or monthly.
Routine screening for the level of 25(OH)D in blood for individuals without specific indications (e.g., hypocalcemia) is not recommended. What should be done with those who still tested their blood and saw low values on paper remains unsaid.
These recommendations apply to individuals without disturbances in vitamin D metabolism, calcium-phosphorus exchange pathology, increased fracture risk, and all that jazz.
So friends, has it become easier? :D