A Vitamin D Level of 22: Whether It Actually Needs Correcting
A single patient with a number that different guidelines would label differently. The disagreement isn't about her health — she's fine — it's about whether a widely used cutoff means what it's usually treated as meaning.
Marisol T., a 41-year-old woman, came in for a routine annual physical and mentioned, almost as an aside, that a friend had recently been told her vitamin D was low and wondered whether she should have hers checked too. She has no bone pain, no fracture history, no fatigue or muscle weakness, gets regular sun exposure from a twice-weekly outdoor running routine, and eats what she describes as a reasonably balanced diet. Her calcium is 9.6 and normal, and nothing in her history flags malabsorption, chronic disease or glucocorticoid exposure. Her 25-OH vitamin D came back at 22 ng/mL — a number that, depending on which reference range her chart happens to display, reads as insufficient or as entirely adequate.
That ambiguity is not a lab error or a formatting quirk, but neither is it quite the live expert disagreement it appears to be. The Endocrine Society's 2011 guideline set a target above 30 ng/mL, and that number still populates most laboratory reference ranges; the Institute of Medicine's report, using a differently derived methodology, set 20 ng/mL as adequate for bone health. The disagreement she is reading off her printout is, however, one the Endocrine Society itself has since abandoned: its 2024 guideline states that it no longer endorses the 30 ng/mL target, having found no trial evidence supporting any outcome-specific threshold, and advises against routine 25(OH)D testing in healthy adults at all. The outcome data is what drove that. VITAL randomized more than 25,000 adults and found no reduction in fracture or major clinical outcomes from supplementation in a general, non-deficient population. Her number of 22 is therefore not contested between two live positions so much as stranded above a threshold one of the two bodies has withdrawn — and produced by a test neither body now recommends she should have had.
Which number is actually the right target
I'd supplement to bring her above 30 ng/mL. That's the number her lab's reference range flags against, it's what the Endocrine Society's 2011 guideline recommended for the general population, and correcting an insufficiency before it worsens is standard, low-risk preventive practice.
I'd question whether 30 is still a target anyone is applying. The Institute of Medicine set 20 ng/mL as adequate for bone health, so by that standard her 22 was never insufficient — but the sharper point is that the Endocrine Society's own 2024 guideline, chaired by Demay, explicitly withdrew the 30 ng/mL target, stating the panel could not identify 25(OH)D thresholds tied to outcome-specific benefits. The two-bodies-disagree framing is a decade out of date.
So she shouldn't be told her level is a problem against a threshold its own author has retracted. What's actually still on the printout is a lab reference range that hasn't caught up.
And the outcome data is what drove that retraction. VITAL randomized more than 25,000 adults and found no reduction in fracture or major clinical outcomes from supplementation in a general, non-deficient population — the kind of result the 2024 panel weighted heavily when it declined to name any threshold at all. The premise that correcting a level like hers produces a clinical benefit rather than a better lab number is not merely unsettled; it is what the current guidance says it could not demonstrate.
Given that, neither number should be presented to her as a health directive. The honest answer is narrower and less satisfying than a disagreement between experts: for an asymptomatic adult under 75 with no risk factors, current guidance from both bodies converges on the recommended dietary allowance, no target level, and no test.
Agreed: tell Marisol directly that the 30 ng/mL threshold her result was flagged against was withdrawn by the body that issued it, that no current guideline names a target level for an asymptomatic adult her age, and that the outcome trials found no clinical benefit at her level — then let her choose whether to supplement rather than presenting any number as a directive.
Not agreed, and explicitly left open: what to do about the laboratory reference range itself, which will keep flagging results against a retracted threshold and generating this conversation for every patient in the low 20s — the endocrinologist wanted it raised with the lab directly, the primary care physician doubted a single practice could move it, and nobody in the room felt equipped to resolve it on the spot.