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Vitamin C and the Renin-Angiotensin-Aldosterone System (RAAS) System: An Intriguing Connection

Written by Portland Clinic of Natural Health on August 7, 2023

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin best known for its role in supporting the immune system, skin health, and aiding in the absorption of iron. Over the years, research has suggested an intriguing connection between Vitamin C and the Renin-Angiotensin-Aldosterone System (RAAS), a hormonal system that regulates blood pressure and fluid balance. Here's a look at the evidence-based link between these two.

What is the RAAS System?

The RAAS system is a complex physiological system that plays a critical role in regulating blood pressure, electrolyte balance, and systemic vascular resistance. It consists of several components, including: (1)

  • Renin: An enzyme produced by the kidneys.
  • Angiotensin I and II: Peptides that are formed after a cascade of enzymatic reactions. Angiotensin II, in particular, causes blood vessels to constrict and stimulates the release of aldosterone, thereby raising blood pressure.
  • Aldosterone: A hormone that prompts the kidneys to retain sodium and water, leading to increased blood volume and pressure.

Vitamin C and RAAS: The Connection

Several research studies have explored the relationship between Vitamin C and the RAAS system:

Antioxidant Properties

One of the most recognized benefits of Vitamin C is its powerful antioxidant capability. Oxidative stress, arising from an imbalance between free radicals and antioxidants, can activate the RAAS system. By reducing oxidative stress, Vitamin C may indirectly modulate the RAAS system and its subsequent effects on blood pressure. (2, 3)

Direct Impact on Components of RAAS

Some studies suggest that Vitamin C can inhibit the secretion of aldosterone. By acting on the aldosterone pathway, Vitamin C can influence sodium and water retention in the body, potentially impacting blood pressure regulation. (4)


Apart from its effects on the RAAS, Vitamin C is also known to enhance the synthesis of nitric oxide, a molecule that causes blood vessels to relax. This vasodilatory effect can further contribute to the regulation of blood pressure. (5)

Influence on Renin Activity

Some animal studies have shown that Vitamin C may decrease plasma renin activity, suggesting another mechanism through which it might impact the RAAS system. (6)

Clinical Implications and Future Directions

Given the potential impact of Vitamin C on the RAAS system, could it be used as a therapeutic agent for conditions like hypertension? While the connection is promising, it's essential to approach this idea with caution. The exact dosage, frequency, and potential side effects of using Vitamin C as a modulator of RAAS need thorough investigation. (7)

Moreover, while Vitamin C supplementation can be beneficial, it's always recommended to obtain nutrients primarily from natural food sources. Foods rich in Vitamin C, such as citrus fruits, strawberries, bell peppers, and broccoli, can be easily incorporated into one's diet.

Vitamin C's Multifaceted Roles in Health

The intricate relationship between Vitamin C and the RAAS system underpins the multifaceted roles vitamins play in our body's physiological processes. As research continues, we will likely uncover more about this intriguing connection and its potential therapeutic implications. Until then, maintaining a balanced diet and consulting with healthcare professionals about supplementation remains paramount.


  1. Patel S, Rauf A, Khan H, Abu-Izneid T. Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies. Biomed Pharmacother. 2017 Oct;94:317-325. doi: 10.1016/j.biopha.2017.07.091. Epub 2017 Jul 31. PMID: 28772209.
  2. Grande MT, Pascual G, Riolobos AS, Clemente-Lorenzo M, Bardaji B, Barreiro L, Tornavaca O, Meseguer A, López-Novoa JM. Increased oxidative stress, the renin-angiotensin system, and sympathetic overactivation induce hypertension in kidney androgen-regulated protein transgenic mice. Free Radic Biol Med. 2011 Nov 15;51(10):1831-41. doi: 10.1016/j.freeradbiomed.2011.08.014. Epub 2011 Aug 25. PMID: 21906672.
  3. Kaźmierczak-Barańska J, Boguszewska K, Adamus-Grabicka A, Karwowski BT. Two Faces of Vitamin C-Antioxidative and Pro-Oxidative Agent. Nutrients. 2020 May 21;12(5):1501. doi: 10.3390/nu12051501. PMID: 32455696; PMCID: PMC7285147.
  4. Bähr V, Möbius K, Redmann A, Oelkers W. Ascorbate and alpha-tocopherol depletion inhibit aldosterone stimulation by sodium deficiency in the guinea pig. Endocr Res. 1996 Nov;22(4):595-600. doi: 10.1080/07435809609043752. PMID: 8969917.
  5. Mortensen A, Lykkesfeldt J. Does vitamin C enhance nitric oxide bioavailability in a tetrahydrobiopterin-dependent manner? In vitro, in vivo and clinical studies. Nitric Oxide. 2014 Jan 30;36:51-7. doi: 10.1016/j.niox.2013.12.001. Epub 2013 Dec 9. PMID: 24333161.
  6. Hwang ES, Choi GY, Kim KJ, Kim MJ, Lee S, Lee JW, Kim DO, Park JH. Vitamin C Lowers Blood Pressure in Spontaneously Hypertensive Rats by Targeting Angiotensin-Converting Enzyme I Production in a Frequency-Dependent Manner. Evid Based Complement Alternat Med. 2022 Jul 8;2022:9095857. doi: 10.1155/2022/9095857. PMID: 35845596; PMCID: PMC9286971.
  7. Guan Y, Dai P, Wang H. Effects of vitamin C supplementation on essential hypertension: A systematic review and meta-analysis. Medicine (Baltimore). 2020 Feb;99(8):e19274. doi: 10.1097/MD.0000000000019274. PMID: 32080138; PMCID: PMC7034722.

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