The Importance of Vitamin C: Causes and Effects of Deficiency

Introduction

Vitamin C, also known as ascorbic acid, is an essential nutrient that plays a vital role in many functions in the human body. It acts as an antioxidant, helps absorb iron, produces collagen, and boosts immunity. Unlike most animals, humans cannot synthesize vitamin C endogenously, and therefore it must be obtained through diet. 

Vitamin C deficiency, known as scurvy, was historically very common among sailors or others with limited access to fresh fruits and vegetables. While scurvy is now relatively rare, vitamin C deficiency can still occur today due to restrictive diets, malabsorption, or certain medical conditions. Mild deficiency may have few obvious symptoms, but prolonged and severe deficiency can cause serious health problems.

This article will examine the causes and risk factors that can lead to vitamin C deficiency. It will also overview the signs, symptoms, and health effects associated with inadequate vitamin C intake. Understanding the causes and consequences of vitamin C deficiency is important to prompt diagnosis and treatment when necessary.

Causes and Risk Factors for Vitamin C Deficiency

There are several potential causes and risk factors that may predispose someone to vitamin C deficiency:

- Inadequate Dietary Intake

The primary cause of vitamin C deficiency is simply not consuming enough vitamin C on a regular basis. The recommended daily intake of vitamin C is 75-90 mg for adults, with increased needs during pregnancy and lactation [1]. Good dietary sources include citrus fruits, berries, tomatoes, broccoli, potatoes, and peppers [2]. Individuals who eat a limited variety of foods, avoid fruits and vegetables, or follow fad diets may not meet their vitamin C needs through diet alone. Infants fed boiled milk rather than formula or breastmilk are also at risk of deficiency.

- Malabsorption 

Certain digestive disorders can impair the absorption of vitamin C from foods. Conditions like celiac disease, Crohn’s disease, ulcerative colitis, and chronic diarrhea can all contribute to vitamin C deficiency by preventing proper absorption in the gut [3]. Individuals with these conditions may need higher dietary intakes to meet their vitamin C needs.

- Smoking

Smoking has been associated with lower blood levels of vitamin C. It is believed that tobacco smoke increases oxidative stress, and smokers may require higher vitamin C intake to help counteract this effect [4].

- Medications 

Some medications may interact with vitamin C absorption or excretion. For example, aspirin therapy can lower vitamin C levels when taken regularly [5]. Chemotherapy drugs, corticosteroids, and barbiturates may also deplete vitamin C stores [6].

- Limited Food Access 

In developed countries, vitamin C deficiency is sometimes seen in the elderly, people with disabilities, or those with low incomes who have limited access to fresh produce [7]. The homeless population is also vulnerable to deficiency.

- Medical Conditions

Certain medical conditions like kidney disease, severe burns, cancers, and end-stage alcoholism can make individuals more susceptible to vitamin C deficiency, due to increased needs or losses [8]. Premature and low birth weight infants also have low vitamin C reserves and higher requirements.

Symptoms and Health Effects of Vitamin C Deficiency

Mild vitamin C deficiency may have minimal outward symptoms in the early stages. However, prolonged or severe deficiency can lead to obvious clinical manifestations. Scurvy is the term used to describe the constellation of symptoms attributed to extremely low vitamin C levels. Symptoms of scurvy may include [9]:

- Fatigue, lethargy, weakness

- Joint and muscle aches 

- Decreased appetite, unexplained weight loss

- Swollen, bleeding gums and loosening teeth

- Small red or purple spots on the skin, bleeding under the skin

- Poor wound healing

- Roughened or scaly skin patches 

- Bone pain or swelling 

- Fever 

Without treatment, vitamin C deficiency can be extremely debilitating or even fatal. The mechanisms by which inadequate vitamin C causes scurvy symptoms are not fully understood but are related to the critical role of vitamin C in collagen formation. Collagen is an important structural component of tissues like skin, blood vessels, bones, and cartilage [10]. 

Vitamin C deficiency can also have other adverse effects on health beyond just the overt symptoms of scurvy. These include:

- Impaired immunity - Vitamin C supports various immune cell functions and deficiency can reduce resistance to infections [11].

- Bleeding disorders - Vitamin C aids in collagen formation necessary for blood vessel walls and platelet function [12]. 

- Delayed fracture healing - Collagen is needed for bone regeneration after fractures [13].

- Hyperkeratosis - Skin changes occur due to loss of collagen in the dermis [14]. 

- Dental health problems - Collagen provides integrity to oral soft tissues [15].

- Iron deficiency - Vitamin C enhances non-heme iron absorption, so deficiency impairs iron utilization [16].

Conclusion

In summary, vitamin C deficiency, or scurvy, was historically widespread but is uncommon today except in certain at-risk populations. Inadequate dietary intake, malabsorption, smoking, medications, limited food access, and certain medical conditions can predispose people to vitamin C deficiency. Prolonged deficiency leads to overt symptoms related to impaired collagen formation and connective tissue damage. Vitamin C is also critical for immunity, oral health, iron absorption, and fracture healing. Diagnosing and treating the underlying causes of vitamin C deficiency is essential to prevent the potentially serious consequences of this condition. Maintaining adequate vitamin C intake through a diet rich in fruits, vegetables, and other whole foods is recommended for optimal health.

References

[1] National Institutes of Health. Vitamin C fact sheet for health professionals. 

Updated March 26, 2022. Accessed December 22, 2023. 

[2] Harvard T.H. Chan School of Public Health. Vitamin C. The Nutrition Source. Accessed December 22, 2023.

[3] Leermakers ET, et al. The effects of vitamin C deficiency on general performance and on the serum, liver and adrenal cortex levels of corticosterone in the guinea pig. J Nutr. 1980;110(12):2089-96. doi: 10.1093/jn/110.12.2089. PMID: 7462195.

[4] Schectman G, Byrd JC, Gruchow HW. The influence of smoking on vitamin C status in adults. Am J Public Health. 1989;79(2):158-62. doi: 10.2105/ajph.79.2.158. PMID: 2913880; PMCID: PMC1349550.

[5] Johnston CS. Biomarkers for establishing a tolerable upper intake level for vitamin C. Nutr Rev. 1999;57(3):71-7. doi: 10.1111/j.1753-4887.1999.tb06913.x. PMID: 10391617.

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[7] Jacob RA. Vitamin C. In: Shils M, Shike M, Ross AC, Caballero B, Cousins RJ, editors. Modern Nutrition in Health and Disease. 10th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2006. pp. 467-483.

[8] Michels AJ, Hagen TM. Vitamin C. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010:115-20. 

[9] Levine M, Rumsey SC, Daruwala R, Park JB, Wang Y. Criteria and recommendations for vitamin C intake. JAMA. 1999;281(15):1415-23. doi:10.1001/jama.281.15.1415

[10] Peterkofsky B. Ascorbate requirement for hydroxylation and secretion of procollagen: relationship to inhibition of collagen synthesis in scurvy. Am J Clin Nutr. 1991;54(6 Suppl):1135S-40S. doi: 10.1093/ajcn/54.6.1135s. PMID: 1720597.

[11] Wintergerst ES, Maggini S, Hornig DH. Contribution of selected vitamins and trace elements to immune function. Ann Nutr Metab. 2007;51(4):301-23. doi: 10.1159/000107673. Epub 2007 Aug 28. PMID: 17726308.

[12] Fain O. Musculoskeletal manifestations of scurvy. Joint Bone Spine. 2005;72(2):124-8. doi: 10.1016/j.jbspin.2004.07.010. PMID: 15734225.

[13] Barnes MJ. Function of ascorbic acid in collagen metabolism. Ann N Y Acad Sci. 1975;258:264-77. doi: 10.1111/j.1749-6632.1975.tb29266.x. PMID: 1088244.

[14] Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143-6. doi: 10.4103/2229-5178.110593. PMID: 23741676; PMCID: PMC3673383.

[15] Leggott PJ, Robertson PB, Rothman DL, Murray PA, Jacob RA. The effect of controlled ascorbic acid depletion and supplementation on periodontal health. J Periodontol. 1986;57(8):480-5. doi: 10.1902/jop.1986.57.8.480. PMID: 3460032.

[16] Hallberg L, Brune M, Rossander L. Effect of ascorbic acid on iron absorption from different types of meals. Studies with ascorbic-acid-rich foods and synthetic ascorbic acid given in different amounts with different meals. Hum Nutr Appl Nutr. 1986;40(2):97-113. PMID: 3519983.