Hematology · Medical Literature
Intermittent exogenous ketosis increases erythropoietin in healthy adults: A randomized, placebo-controlled study with preliminary sex-specific observations.
Abstract
Exogenous ketosis may stimulate erythropoietin (EPO), yet its impact on erythropoiesis, iron metabolism, and potential sex-specific responses in humans remains unknown. We investigated these effects in healthy adults using oral β-hydroxybutyrate ketone monoester (KE) to induce intermittent ketosis. Acute EPO responses to a single dose of KE were assessed in 16 healthy adults (pre-post), followed by a 2-week randomized study (KE twice daily vs. placebo). After 2 weeks, EPO levels with intermittent ketosis were approximately 30% higher (95% CI 6, 60), p = 0.01, an effect more evident in females (9.7 IU/L (95% CI 6.0, 13.5) vs. 6.4 IU/L (95% CI 4.0, 8.8), p = 0.008) than in males (10.7 IU/L (7.2, 14.2) vs. 9.6 IU/L (6.3, 12.9), p = 0.46). Ferritin was elevated in females with KE vs. placebo (42 μg/L vs. 16 μg/L, p < 0.001). Hemoglobin and red blood cell count were unaffected at 2 weeks. Over 2 weeks, intermittent exogenous ketosis was associated with a modest increase in erythropoietin levels, with a stronger signal in females. Although hemoglobin and red blood cell count did not change significantly, females showed higher ferritin levels and a trend toward increased hematocrit, suggesting subtle effects on erythropoietic stimulation and iron handling.
Clinical relevance
Does intermittent exogenous ketosis induced by twice-daily oral β-hydroxybutyrate ketone monoester (KE) over 2 weeks elevate erythropoietin (EPO), and are there sex-specific differences in EPO, iron metabolism, and erythropoietic outcomes in healthy adults? __SNAPSHOT__ {"studyDesign":"Two-phase study: (1) pre-post acute assessment (single-dose KE), followed by (2) 2-week randomized, placebo-controlled trial (parallel group)","setting":"Not reported (institutional affiliation suggests Aarhus University Hospital, Denmark, based on author profiles; clinical setting not explicitly stated in abstract)","sampleSize":"n=16 for acute pre-post phase; randomized phase group sizes not explicitly reported in abstract","population":"Healthy adults (sex composition not fully detailed in abstract; males and females included); specific inclusion/exclusion criteria not reported in abstract","intervention":"Oral β-hydroxybutyrate ketone monoester (KE) twice daily for 2 weeks to induce intermittent exogenous ketosis","comparator":"Placebo (twice daily for 2 weeks)","primaryOutcome":"Serum erythropoietin (EPO) concentration after 2 weeks of intermittent ketosis; secondary outcomes included hemoglobin, red blood cell (RBC) count, and ferritin","followUp":"2 weeks (randomized phase); single-dose acute assessment also performed","fundingSource":"Not reported in abstract"}
Key findings
After 2 weeks of twice-daily ketone monoester supplementation, EPO levels were approximately 30% higher in the KE group compared to placebo (95% CI: 6%, 60%; p=0.01). In absolute terms, EPO was higher in females receiving KE versus placebo (9.7 IU/L [95% CI 6.0, 13.5] vs. 6.4 IU/L [95% CI 4.0, 8.8]; p=0.008), while the difference in males did not reach statistical significance (10.7 IU/L [95% CI 7.2, 14.2] vs. 9.6 IU/L [95% CI 6.3, 12.9]; p=0.46). Ferritin was markedly elevated in females receiving KE compared to placebo (42 µg/L vs. 16 µg/L; p<0.001); ferritin data in males were not reported in the abstract. Hemoglobin and red blood cell count were not significantly different between groups at 2 weeks. NNT is not calculable from the data reported. No clinically important adverse events were described in the abstract.
Practice implications
This study establishes that 2 weeks of intermittent exogenous ketosis via oral KE produces a statistically significant ~30% relative increase in circulating EPO in healthy adults. The signal was driven primarily by females, who showed both a statistically significant EPO response and a striking elevation in ferritin compared to placebo, suggesting a possible sex-specific interaction with iron metabolism and EPO signaling. Males did not demonstrate a statistically significant EPO response at this dose and duration. Critically, the EPO rise did not translate into measurable increases in hemoglobin or RBC count at 2 weeks, leaving functional erythropoietic significance unestablished. The 2-week interval is likely too short for mature red cell production to be reflected in circulating hemoglobin; longer follow-up is required to determine whether the EPO stimulus yields clinically meaningful erythropoiesis. The findings do not apply to patients with anemia, renal impairment, hematologic disorders, or those on erythropoiesis-stimulating agents — groups that were not represented. Sex-specific results are described by the authors as 'preliminary observations,' appropriate given the study's small sample and post-hoc or exploratory nature of sex stratification. The ferritin elevation in females warrants careful interpretation: it may reflect iron redistribution, altered hepcidin signaling, or an inflammatory response rather than iron repletion. Practice should not change on the basis of this study alone. __LIMITATIONS__ Very small sample size (n=16 for acute phase; randomized arm sizes not reported in abstract), severely limiting statistical power and precision of sex-stratified analyses.,Sex-specific findings are explicitly labeled 'preliminary' by the authors, suggesting they were exploratory or underpowered subgroup analyses rather than pre-specified primary endpoints.,Short 2-week intervention duration is insufficient to capture downstream erythropoietic endpoints such as reticulocyte count, red cell mass, or hemoglobin; the absence of hemoglobin change may simply reflect timeline constraints.,The abstract is truncated — key methodological details (randomization procedure, blinding, placebo composition, exact group sizes, adverse event reporting, and full statistical model) are not available for appraisal. Assessment is limited to abstract-level data.,Healthy adult population limits generalizability to clinical populations with anemia, renal disease, or iron deficiency.,The marked ferritin elevation in females (42 vs. 16 µg/L, p<0.001) is mechanistically unexplained; acute phase reactant elevation, hepcidin modulation, or assay variability cannot be excluded.,Funding source is not reported, precluding assessment of potential industry-related bias.,Surrogate endpoint (serum EPO) does not confirm clinically meaningful erythropoiesis; EPO elevation without downstream red cell mass increase has uncertain clinical relevance.,Absence of reticulocyte count, soluble transferrin receptor, hepcidin, and bone marrow data limits mechanistic interpretation.,Generalizability is further constrained by the exclusive use of healthy adults, a specific KE formulation, and a twice-daily dosing schedule. __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ Two weeks of twice-daily oral β-hydroxybutyrate ketone monoester produces a statistically significant ~30% relative increase in serum EPO in healthy adults, with a stronger and more consistent signal in females who also demonstrated markedly elevated ferritin; males did not show a significant EPO response. However, hemoglobin and RBC count were unchanged at 2 weeks, leaving functional erythropoietic significance unproven, and the sex-specific findings are preliminary given the small sample. This exploratory study is hypothesis-generating and should not alter clinical practice; adequately powered, longer-duration trials in relevant patient populations are required before any therapeutic application can be considered.