Is dietary deficiency of calcium a factor in rickets? Use of current evidence for our understanding of the disease in the past

•Role of calcium deficiency in rickets is assessed by review of relevant literature.•Evidence to support the role of dietary calcium deficiency in rickets is weak.•Rickets is essentially an indicator of vitamin D deficiency in palaeopathology.•Dietary calcium deficiency may occasionally play a minor role in the development of rickets.•Multivariate analysis may help identify risk factors for rickets in the past.