Increasing Leukocyte and Neutrophil Count with Vitamin C Supplementation: A Case Report

Abstract

Background

Current literature details the use of intravenous vitamin C to improve leukopenia; however, the use of oral vitamin C to improve leukopenia has been underexplored.

Objective

This case study aimed to evaluate whether supplemental oral vitamin C could elevate leukocyte values in a 67-year-old African American male.

Case Report

The patient had leukopenia for over 30 years, which prompted additional medical evaluation over the years. This evaluation included two bone marrow biopsies, both of which yielded normal findings. Although the individual was not traumatized by the medical concern and extensive testing for his neutropenia, he wanted to explore whether vitamin C could address his leukopenia. Over the course of one year, the individual took 5000-7000 mg of vitamin C daily in powdered and liposomal forms.

Findings

5000 – 7000 mg of vitamin C successfully increased white blood cell count (near the standard normal limits) and absolute neutrophil count in the African American male patient.

Conclusion

This case report details the use of supplemental oral vitamin C as a single intervention to improve leukopenia and neutropenia. However, more research is needed to determine if smaller doses could yield similar results.

Introduction

Leukopenia is defined as a white blood cell count (WBCc) below 4000 cells per microliter, while neutropenia is an absolute neutrophil count (ANC) below 1500 cells per microliter.¹ Leukocytes are critical to the immune response and get activated in response to injury or pathogens. Neutrophils, on the other hand, are the most common leukocytes, and thus their deficiency significantly contributes to leukopenia. The primary role of the neutrophil is to phagocytose pathogens; therefore, neutrophil deficiency can impair immune function. Common causes of neutropenia are autoimmune conditions, infections, drug complications, deficiencies of folate, vitamin B12, or copper, or leukemia.² Bone marrow biopsies are performed to evaluate neutropenia when it is severe or unexplained. The biopsies help to determine whether there are low or normal neutrophil reserves in the bone marrow, which in turn help assess the etiology of the neutropenia.² What is less commonly considered is Benign Ethnic Neutropenia (BEN). BEN is a naturally occurring variation in individuals with naturally lower neutrophil counts due to their genetic background.³

Vitamin C is a water-soluble antioxidant. It stimulates WBC production and accumulates in neutrophils, protecting them from oxidative damage. The antioxidant properties of vitamin C protect leukocytes from oxidation, which naturally occurs during phagocytosis.⁵

This case study outlines how a 67-year-old African American male improved his long-standing leukopenia and neutropenia through supplemental oral vitamin C. Since vitamin C supports WBC production, the patient explored its use in resolving his Leukopenia and neutropenia.

Case Report

Narrative

A 67-year-old African American male presented to his PCP in November 2023 with a WBCc of 1.8 thousand cells/μL (standard reference range is 1500 – 8000 cells/μL; American board⁵) and an ANC of 730 cells/μL (standard reference range is 1,500 – 8,000 cells/μL; neutropenia is <1500 cells/μL5) (refer to Table 1 for timeline and Table 2 for clinical findings). All remaining complete blood count (CBC) values fell within the standard reference range. Due to the low WBCc and apparent neutropenia, the patient was referred to a hematologist for a bone marrow biopsy to investigate possible leukemia. This was the second time the patient underwent a bone biopsy to test for leukemia. In the early 1990’s, he also had a bone biopsy due to his low WBCc. The patient never exhibited symptoms related to low WBCc, such as easy bruising, frequent infections, fever, or fatigue. The patient maintained a healthy lifestyle, as evidenced by running several days per week, eating a primarily whole-food, plant-based diet, and maintaining a consistent meditation practice. The patient did not take any medications or supplements except for the occasional use of 1000 mg of vitamin C (Emergen-C) when he got a cold or was traveling, plus a multi-vitamin once or twice per week. After reviewing Linus Pauling’s work on vitamin C, the patient became interested in using vitamin C to support his WBCc production.⁴ Since he did not exhibit any symptoms of poor immune function, he did not consider trying to boost the functioning of his immune system via increased intake of other micronutrients.

Table 1.

Timeline of the Case

2023-11-15	The patient underwent a routine annual blood work. WBCc was 1.8 thousand cells per microliter, and ANC was 730 cells per microliter; all other labs were in the normal range. The standard reference range for WBCc is 4000-11 000 cells per microliter, and ANC is 1500-8000 cells per microliter (ANC below 1500 cells per microliter is considered neutropenia). The Primary Care Provider (PCP) noticed the low WBCc and referred the patient to a hematologist for investigation of possible leukemia.
2023-12-03	The patient underwent a bone marrow biopsy to test for leukemia. The test was negative.
2024-03-01	The patient met with a nutritionist due to the low WBCc and low ANC. A vitamin C protocol of 5000 – 7000 mg per day was recommended and started.
2024-03-27	The patient had follow-up blood work with PCP for WBCc, after nearly 4 weeks on the vitamin C regimen. WBCc increased to 2 thousand cells per microliter. ANC increased to 978 cells per microliter.
2024-07-10	The patient underwent follow-up blood work with PCP for WBCc. WBCc increased to 2.1 thousand cells per microliter. Patient continued his vitamin C regimen without changes.
2025-01-08	The patient had preoperative bloodwork. WBCc increased to 2.9 thousand cells per microliter. ANC increased to 1450 cells per microliter.
2025-04-03	Annual check-up with PCP. WBCc approached the normal range at 3.2 thousand cells per microliter. ANC of 2134 cells per microliter was within the normal range.

Table 2.

Clinical Findings

Type	Value	Unit
2023-11-16
Absolute Neutrophil Count	730	cells/μL
WBC (Total white blood cells)	1800	cells/μL
2023-12-14
Absolute Neutrophil Count	740	cells/μL
WBC (Total white blood cells)	1900	cells/μL
2024-03-28
Absolute Neutrophil Count	978	cells/μL
WBC (Total white blood cells)	2000	cells/μL
2024-07-11
Absolute Neutrophil Count	1000	cells/μL
WBC (Total white blood cells)	2100	cells/μL
2025-01-09
Absolute Neutrophil Count	1450	cells/μL
WBC (Total white blood cells)	2900	cells/μL
2025-04-04
Absolute Neutrophil Count	2134	cells/μL
WBC (Total white blood cells)	3200	cells/μL

To avoid further unnecessary testing due to continued low WBCc, the patient sought guidance from his nutritionist, who suggested a regimen of Vitamin C would be appropriate. The protocol began in early March of 2024 and consisted of two forms of vitamin C (Designs for Health Vitamin C powder and Designs for Health Liposomal Vitamin C). The recommended daily allowance of vitamin C for men is 90 mg/day, while the tolerable upper limit is 2000 mg/day. The National Institutes of Health (NIH) states, “Vitamin C has low toxicity and is not believed to cause serious adverse effects at high intakes.”⁶ The patient took 5000 mg - 7000 mg/day, to gastric tolerance. In the morning and afternoon, the patient took 2 divided doses of Design for Health Vitamin C powder mixed with 10 oz of water. A standard serving is one scoop (teaspoon), equaling 2000 mg of vitamin C. The patient took a heaping scoop, increasing this dosage to roughly 3000 mg per serving. Before bed, the patient took 1-2 doses of 1000 mg liposomal Vitamin C orally. He chose liposomal Vitamin C at night to avoid a large amount of water before bed. He would take a second dose of liposomal Vitamin C if he felt like he might be catching a cold or felt fatigued. The patient followed this vitamin C protocol diligently from March of 2024 through the final blood work in April of 2025. In late March 2024, four weeks after initiating the high-dose vitamin C protocol, his WBCc was measured at 2.0 thousand cells/μL, and ANC increased to 978 cells/μL (Table 2). In April 2025, his WBCc had risen to 3.2 thousand cells/μL, almost double his initial WBCc. After one year of supplementation, his neutrophil count further increased to 2134 cells/μL (Table 2). The patient continues to take 3000 mg of supplemental oral vitamin C daily.

Discussion

Population data reveal that people of African descent have a lower WBCc than their white counterparts. On average, it is approximately 700 cells per microliter lower. It is also known that about 4.5% of African Americans, and up to 50% of Africans, have the Duffy-null phenotype.⁷ The Duffy-null phenotype is clinically significant because it allows resistance to malaria.⁷ Those with the Duffy-null phenotype exhibit an ANC below 1500 cells/uL (proposed standard reference range for Duffy-null phenotype is 1210/μL to 5390/μL) and is associated with BEN or neutropenia without increased infection risk.^7,8 This phenotype is primarily seen in people of African descent but is also reported among Yemenite Jewish, Caribbean, and West Indian descent.⁴ Despite the lower counts for WBCs, this group does not show any symptoms of impaired immune function, such as an increased risk of infections.³

In line with people of African descent, this patient did not exhibit symptoms of impaired immune function despite his low WBCc. While his low WBCc did not appear to be pathophysiologic, it was the impetus for undergoing two bone marrow biopsies over a few decades, both of which yielded normal results. To avoid future medical concerns and intervention, the patient decided to attempt to elevate his WBCc. There has not been significant research on vitamin C in healthy individuals, but we do know that vitamin C can reportedly enhance WBC production.⁹ Additionally, vitamin C may play a role in the maturation and differentiation of B-cells and T-cells, potentially by epigenetic modulation of gene expression.¹⁰

Vitamin C titration to bowel tolerance is a concept documented by Robert Cathcart as the highest amount of vitamin C a patient can tolerate without causing diarrhea. In a study by Cathcart, subjects were able to tolerate up to 15 g of ascorbic acid daily without diarrhea.¹¹The same study found that when someone was ill or under stress, they were able to tolerate even higher levels of ascorbic acid, and there was less elimination of vitamin C in urine.¹¹

The tolerable upper limit (TUL) of vitamin C for people older than 19 years is currently set at 2 g according to the NIH.¹² While current guidelines indicate that vitamin C is generally safe, discretion in dosing vitamin C should be considered as high doses can be problematic for some populations, such as those with hemochromatosis or a history of hyperoxaluria.¹² Further, according to the Pauling Institute, vitamin C absorption efficiency is observed at 100% when ingesting up to 200 mg at a time. Doses over 500 mg result in less absorption efficiency, and once plasma concentrations reach saturation, additional vitamin C is excreted in the urine.¹²

Foster and colleagues used IV vitamin C at 70 g per treatment, administered twice a week, to treat an individual with neutropenic fever due to chemotherapy for leukemia. The patient’s WBCc increased from 0.29 × 109/L to 4.0 × 109/L in six weeks.¹³ However, the mechanism for vitamin C absorption is different between oral and IV routes. A study involving 11 adults showed that liposomal vitamin C achieved higher circulating vitamin C concentrations than unencapsulated varieties.¹⁴ By using a combination of powdered and liposomal Vitamin C, the patient was able to manage the timing of his fluid intake while adhering to his self-directed protocol. This allowed him to meet his goal of normalizing both his WBCc and his neutrophil count over 13 months.

Patient Perspective

I have had low white blood count for at least 35 years, likely all my life. I remember going for my annual physical about 35 years ago, and the doctor noted my white blood count was quite low. The doctor seemed quite distressed; I was sent to a hematologist and subsequently for a bone marrow biopsy. I know now that the doctor was concerned about leukemia. Flash forward to the most recent two years, and again at a physical, my PCP (a different doctor) noticed a low white blood count; this doctor also sent me to a hematologist, and I again was given a bone marrow biopsy. In my discussion with the hematologist, I indicated that I very rarely get sick, maybe a cold every other year, no Covid, although many around me had Covid. I do not easily bruise, and if I do, the bruise does not linger. I was aware that, as an African American, my WBC “norm” could be lower than the general population, although my doctor did not seem to consider that information.

I used to only use C supplements on a somewhat regular basis as part of my overall health regimen: eat well, lots of plants, get regular exercise, and take some supplements. Also, because I used to travel a great deal for work and I was exposed to crowds of people in airports, airplanes, hotels, conference rooms, and gyms… I wanted some extra immune support that vitamin C supposedly offers. Some of that was motivated by the work I had read from Linus Pauling before getting my master’s degree. However, my recent physical brought my low WBC back to the front of my brain; I met with a nutritionist, and it was advised that this vitamin C regimen could have success in raising my WBC.

Conclusion

Among the African American community, it is common to have a lower WBCc than other ethnicities. If doctors are unaware of this, it can lead to needless testing, increased medical bills, and unnecessary time away from work, as our patient experienced. Due to unnecessary testing, the patient wanted to increase his WBCc and ANC. Through a dose of 5000 mg -7000 mg of vitamin C daily, our patient successfully increased his WBCc and ANC. We believe that more research is needed to determine if smaller doses could yield similar results.