Vitamin C Status of US Adults Assessed as Part of the National Health and Nutrition Examination Survey Remained Unchanged between 2003–2006 and 2017–2018

Abstract

Background We compared serum vitamin C (VIC) status of the adult (≥20 y) US population in the National Health and Nutrition Examination Survey (NHANES) 2017–2018 with combined data from 2003–2004 and 2005–2006. Methods VIC was measured using HPLC with electrochemical detection. Mean data were stratified by age, sex, race/Hispanic origin, income, body mass index, dietary intake, supplement use, and smoking status. Prevalence of VIC deficiency (<11.4 μmol/L) was calculated. Results In NHANES 2017–2018, the mean VIC was 8 μmol/L higher in people ≥60 y compared with those 20–59 y of age, 10 μmol/L lower in men vs women, 8 μmol/L lower in low vs high income, 11 μmol/L lower in obese vs healthy weight, and 15 μmol/L lower in smokers vs nonsmokers. Differences in mean VIC across race/Hispanic origin groups ranged from 2 to 7 μmol/L. Mean VIC was 27 μmol/L higher with vitamin C-containing supplement use and positively associated (Spearman ρ = 0.33; P < 0.0001) with increasing dietary intake. The associations between mean VIC and the investigated covariates were generally consistent and the prevalence of deficiency was not significantly different between survey periods (6.8% vs 7.0%; P = 0.83). However, a few subgroups had double the risk. We found no significant survey differences in mean VIC (51.2 vs 54.0 μmol/L; P = 0.09). Conclusions Overall VIC status of the US adult population has remained stable since last assessed in the NHANES 2005–2006 survey. Vitamin C deficiency remained high for those with low dietary intake and who smoke.

Does Aging Have an Impact on Vitamin C Status and Requirements? A Scoping Review of Comparative Studies of Aging and Institutionalisation

“…Others have shown an inverse association between vitamin C status and ageing in men only [ 22 ] or even a small increase in vitamin C status in non-smoking older people [ 21 ], with the latter being attributed to higher supplemental intake in the older group. Large epidemiological studies have shown opposite trends to earlier studies, with an analysis of the US National Health and Nutrition Examination Surveys (NHANES 2003–2006 and 2017–2018) indicating higher vitamin C status and a lower or comparable prevalence of deficiency (<11 µmol/L) in people aged ≥60 [ 16 , 17 , 18 ]. The increased vitamin C status in older people appeared to be primarily related to higher vitamin C supplement intake [ 16 ].…”

“…Large epidemiological studies have shown opposite trends to earlier studies, with an analysis of the US National Health and Nutrition Examination Surveys (NHANES 2003–2006 and 2017–2018) indicating higher vitamin C status and a lower or comparable prevalence of deficiency (<11 µmol/L) in people aged ≥60 [ 16 , 17 , 18 ]. The increased vitamin C status in older people appeared to be primarily related to higher vitamin C supplement intake [ 16 ]. Age categories <60 or <65 did not appear to be associated with differences in vitamin C status in the NHANES cohorts or the large French SU.VI.MAX study [ 16 , 17 , 18 , 19 , 20 ].…”

“…The identified publications were categorised into age-related studies ( n = 19) [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], requirements-related studies ( n = 7) [ 22 , 26 , 35 , 36 , 37 , 38 , 39 ], and residence-related studies ( n = 11) [ 23 , 27 , 33 , 34 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ], with a number of studies spanning multiple categories [ 22 , 23 , 26 , 27 , 33 , 34 ].…”

“…The increased vitamin C status in older people appeared to be primarily related to higher vitamin C supplement intake [ 16 ]. Age categories <60 or <65 did not appear to be associated with differences in vitamin C status in the NHANES cohorts or the large French SU.VI.MAX study [ 16 , 17 , 18 , 19 , 20 ]. Studies carried out in hospitalised patients contrasted those carried out in the general population ( Table 1 ), showing decreased vitamin C status (in the hypovitaminosis C range) and an increased prevalence of deficiency in older hospitalised patients [ 27 , 28 ].…”

“…Furthermore, epidemiological studies of the general population indicate that older people (aged ≥ 60 years) had a higher vitamin C status and a comparable or lower prevalence of deficiency than younger people [ 17 , 18 ]. The higher vitamin C status in older people was associated with intake of vitamin-C-containing supplements in the US cohorts [ 16 ]. Of note, there has been a gradual trend over time towards the increased usage of dietary supplements in the US, with adults aged ≥60 years being the largest multivitamin users [ 47 ].…”