Vitamin D insufficiency and deficiency: in search of a bone disease.
Level 5 - mechanism / opinion, no new human data
Narrative review evaluating clinical and biochemical thresholds for vitamin D without systematic review methodology or primary data.
PubMed 41314906 · doi:10.1016/j.pathol.2025.08.009
What was done
This narrative review evaluated clinical, biochemical, densitometric, and histomorphometric evidence regarding diagnostic thresholds for 25-hydroxyvitamin D [25(OH)D] deficiency (<30 nmol/L) and insufficiency (30 to 50 or 75 nmol/L) in community dwellers and institutionalized or high-risk populations.
What was found
The abstract reports that 25(OH)D levels between 30 and 75 nmol/L in community dwellers show little convincing evidence of secondary hyperparathyroidism, impaired bone volume, microarchitectural defects, or osteomalacia. At levels <30 nmol/L, only a minority of individuals exhibit modest serum parathyroid hormone elevations, and most lack biochemical or bone structural abnormalities. The abstract provides no specific numerical values, percentages, or sample sizes.
Why it matters
It highlights that diagnostic cutoffs for vitamin D 'insufficiency' may overstate bone disease risk in healthy community dwellers, whereas true bone-compromising deficiency is primarily relevant in high-risk groups such as nursing home residents or individuals with malabsorption.
Limits
This is a narrative review without systematic search protocols, quantitative data extraction, or meta-analytic pooling reported in the abstract. The abstract notes that available meta-analyses are limited by confounding and that few well-designed factorial trials exist comparing vitamin D with and without calcium.
Cited by
- context Parathyroid hormone levels serve as an indirect test to assess vitamin D absorption and severe deficiency.