Global Vitamin C Status and Prevalence of Deficiency: A Cause for Concern?

Abstract

Vitamin C is an essential nutrient that must be obtained through the diet in adequate amounts to prevent hypovitaminosis C, deficiency and its consequences-including the potentially fatal deficiency disease scurvy. Global vitamin C status and prevalence of deficiency has not previously been reported, despite vitamin C's pleiotropic roles in both non-communicable and communicable disease. This review highlights the global literature on vitamin C status and the prevalence of hypovitaminosis C and deficiency. Related dietary intake is reported if assessed in the studies. Overall, the review illustrates the shortage of high quality epidemiological studies of vitamin C status in many countries, particularly low- and middle-income countries. The available evidence indicates that vitamin C hypovitaminosis and deficiency is common in low- and middle-income countries and not uncommon in high income settings. Further epidemiological studies are required to confirm these findings, to fully assess the extent of global vitamin C insufficiency, and to understand associations with a range of disease processes. Our findings suggest a need for interventions to prevent deficiency in a range of at risk groups and regions of the world.

Keywords: LMIC; communicable disease; dietary intake; hypovitaminosis C; infection; low and middle income; non-communicable disease; supplement; vitamin C deficiency; vitamin C status.

Figure 1

Global adult vitamin C status. The area of the bubble represents the size of the study. Blue bubbles represent high-income countries; orange bubbles represent low- and middle-income countries. Vitamin C status cutoffs: red—deficient (<11 µmol/L); orange—hypovitaminosis C (<23 µmol/L); yellow-inadequate (<50 µmol/L); green—adequate (>50 µmol/L).

Figure 2

Summary of global vitamin C status (A) and intake (B) and prevalence of hypovitaminosis C (C) and vitamin C deficiency (D). Key: HIC—high-income countries; LMIC—low- and middle-income countries. Hypovitaminosis C, <23 µmol/L; vitamin C deficiency, <11 µmol/L. Numbers above bars indicate total number of individuals assessed.