Two fruit a day make bowel movements more frequent and more comfortable, at least as well as standard fibre supplements and with fewer complaints. Two gold fruit fill a vitamin C shortfall completely, which in people who were short came with better reported energy and mood. Blood pressure, cholesterol and sleep findings remain unresolved. The main hazard is allergy. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Plasma vitamin C | 60–80 µmol/L | Confirms saturation and predicts the mood and vitality response |
| Complete spontaneous bowel movements per week | No established target; ≥1 extra per week is the trial-defined response | Primary endpoint in every constipation trial |
| Serum ferritin | 50–100 µg/L | Identifies who gains from the iron-absorption effect and who is at overload risk |
| Serum potassium | 4.0–4.5 mmol/L | Detects drift from the potassium load in reduced kidney function |
| eGFR | ≥90 mL/min/1.73 m² | Determines whether the potassium load matters at all |
| hs-CRP | <1.0 mg/L | Tracks the inflammation that pooled analysis found kiwi does not change |
| LDL-C and ApoB | LDL-C <100 mg/dL; ApoB <80 mg/dL | Tests the contested cholesterol claim in the individual |
| HbA1c | 4.8–5.2% | Checks whether repeated carbohydrate exchange shifts average glucose |
| Blood pressure | <120/80 mmHg | Tests the conflicted blood-pressure signal directly and cheaply |
| 24-hour urinary oxalate | <25 mg/day for stone formers | Relevant only to those with calcium oxalate stone history |
| Specific IgE to Act d 1 | No established numeric target; any detectable level is meaningful in the presence of symptoms | Distinguishes systemic-risk primary allergy from pollen cross-reaction |
Cadence: Plasma vitamin C and the bowel diary at baseline and four weeks; serum potassium at four weeks only where kidney function is reduced or potassium-retaining drugs are in use; thereafter ferritin, lipids and vitamin C every 6–12 months. Warfarin users: international normalised ratio two weeks after starting and after any deliberate change in daily amount.