Vitamin C deficiency is more frequent in people living in areas of socio-economic disadvantage, prompting calls for targeted public health intervention.
More action is needed to encourage people living in lower socio-economic areas to consume more foods rich in vitamin C, following a study which found that residents of certain areas of New South Wales experience vitamin C deficiency more commonly than generally recognised.
Vitamin C deficiency is a significant public health problem in low and high income countries and is associated with socio-economic disadvantage and the resultant limited access to nutritious food.
“The distribution of prosperity and socio‐economic disadvantage in NSW is uneven in both urban and regional areas,” Dr Puja Bhattacharyya and her colleagues wrote in their research in the Medical Journal of Australia.
“Disadvantage influences diet, including the consumption of fresh fruit and vegetables, and thereby the risk of vitamin C deficiency.”
Dr Puja Bhattacharyya is a haematology specialist based in Sydney.
Severe deficiency can cause hypovitaminosis C, also known as scurvy.
The largest Australian study
The study, which was the largest study of risk factors for vitamin C deficiency in Australia, examined over 12 000 vitamin C tests carried out at the Royal Prince Alfred Hospital in Sydney between 2017 and 2021.
The researchers found that 24.5% of people tested had significant vitamin C deficiency and 29.9% of participants had hypovitaminosis C.
The proportions of significant deficiency increased as postcode-level socio-economic disadvantage increased.
“In our univariable multinomial analyses, the likelihood of hypovitaminosis C and significant deficiency relative to findings of normal vitamin C levels increased with age, level of local disadvantage, and geographic remoteness,” Dr Bhattacharyya and colleagues wrote.
“Men were more likely to have a significant deficiency than women, but not hypovitaminosis C.”
The researchers noted an increase in the number of vitamin C tests undertaken in each year of the study period, but the deficiency rate did not decline after 2018.
“This suggests that awareness among clinicians of the importance of vitamin C has grown, but also that some people with symptoms of deficiency do not undergo assessment or are unaware of the risk of deficiency, and that not all clinicians order tests when indicated,” Dr Bhattacharyya and colleagues wrote .
Lessons from the COVID-19 pandemic
The researchers found that the number of people with significant deficiency declined each year of the study period until 2020, when the probability of people under the age of 75 years having significant deficiency rose again.
“The reason for this rise, and for an even larger rise in the probability of hypovitaminosis C, may be related to changes in diet during [coronavirus disease 2019] COVID‐19 lockdowns, including altered consumption of fresh fruit and vegetables during this period,” Dr Bhattacharyya and colleagues wrote.
Despite this, the researchers noted that economic stimulus measures implemented by the Australian Government at the height of the COVID-19 pandemic did lead to people who were receiving welfare payments being able to eat healthier food more regularly.
“As people living in areas of lower socio‐economic status consume less healthy food and drink than those in higher status areas, increasing their household income could increase vitamin C intake,” Dr Bhattacharyya and colleagues wrote.
Targeted intervention needed
The research authors suggest several strategies for increasing the consumption of foods rich in vitamin C, including education, national dietary guidelines, and making fresh fruit and vegetables more affordable.
Due to the prevalence of vitamin C deficiency in people living with socio-economic disadvantage, the research authors have called for population assessment of vitamin C levels in order to determine how best to target these potential interventions.
“A more comprehensive investigation of the prevalence of vitamin C deficiency could identify groups for whom ensuring the recommended daily intake of vitamin C might be an inexpensive and effective public health intervention,” Dr Bhattacharyya and colleagues wrote.
Read the research in the Medical Journal of Australia
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