Ingredient transparency
What's in your Fiks
Formulations grounded in UK National Diet and Nutrition Survey (NDNS) 2019–2023 data. Select your Fiks to see exactly what's in each daily sachet, the RDA percentage, and why we chose each ingredient.
Why six, not sixty.
Most supplements try to do everything. We don't.
Each Fiks formulation is built from national dietary deficiency data (NDNS) for your specific age and gender group, six cohorts, six formulations, nothing generic.
That means fewer ingredients, not more, only the ones the data says you're likely missing. No mega-dose multivitamin. No guessing.
- Female 16–29
- Female 30–49
- Female 50+
- Male 16–29
- Male 30–49
- Male 50+
| Nutrient & NDNS Finding | UK Reference Intake | Fiks Dosage | % of Reference Intake | Why This Form |
|---|---|---|---|---|
Vitamin D 18–31% of adults deficient; higher in Scotland | 10mcg/day | 1000IU (25mcg cholecalciferol) | 250% | Standard winter supplementation; essential at Scottish latitude |
Folate 83% of women 16–49 below neural tube defect risk threshold | 200mcg/day | 400mcg (Methyl Folate / Quatrefolic) | 200% | Methylated form works where synthetic folic acid often fails |
Iron 25% of women 16–49 below the Lower Reference Nutrient Intake (LRNI) | 14.8mg/day | 18mg (Bisglycinate) | 122% | Absorbed roughly 2.5x better than ferrous sulphate; minimal gastrointestinal (GI) side effects |
Magnesium 19% of women in their twenties below the LRNI | 270mg/day | 300mg (Bisglycinate) | 111% | 40–50% bioavailability vs ~4% for magnesium oxide |
Selenium 50.3% of UK females below the LRNI | 60mcg/day | 55mcg (Selenomethionine) | 92% | Bioavailable organic form; conservative dose |
Iodine 29% decline in urinary iodine in women of childbearing age, 2013–2023 | 140mcg/day | 150mcg (Potassium Iodide) | 107% | Rowett-approved addition, June 2026; falling dairy intake and rising plant-based diets are driving this decline |
Safety & compliance
- No ingredient exceeds the Safe Upper Limit set by the Food Standards Agency (FSA) or European Food Safety Authority (EFSA)
- Fat-soluble vitamins (D, K2) within established safe daily intake ranges
- All bioavailable forms selected to maximise absorption and minimise gastrointestinal (GI) side effects
- CoQ10 and Vitamin K2 grounded in independent clinical literature
- Omega-3 dosages align with cardiovascular and inflammatory disease prevention guidelines
- No ingredient interactions between sachet contents; safe to take simultaneously
- All dosages per daily sachet (one sachet per day)
Data sources
National Diet and Nutrition Survey (NDNS) 2019–2023: Department of Health and Social Care & Food Standards Agency. Delivered by the Medical Research Council (MRC) Epidemiology Unit, University of Cambridge. Read the official report
UK Reference Intakes: Food Standards Agency & Department of Health. Current recommendations as of 2024.