What UK bodies actually
need in winter
From October to March, UK adults face lower vitamin D, weaker immune defences, disrupted sleep, and more fatigue. Here's the evidence-based guide to what to take and why.
Impervious — ahead of winter, others suffer, you prepared
Im
Pervious
Fortified — illness can't touch you
Ahead
Of Winter
Prep now — don't wait to get sick
Others
Suffer
You prepared = you stay well
October to March is peak deficiency season in the UK
Sunlight drops below the threshold for vitamin D synthesis — the NHS advises supplementation for all UK adults through winter. The window is now.
NHS-backed — NHS-backed supplements
Oct–Mar
Supplementation season
UK sunlight is insufficient for vitamin D synthesis for 6 months of the year
NHS-cited
Vitamin D guidance
NHS advises everyone in the UK to take 10mcg vitamin D daily through winter
1,276+
Winter wellness customers
Medibro customers who start a winter protocol each October
Why UK winters demand supplementation
Zero Vitamin D from October to April
The UK is at latitude 51–60°N. Between October and April, the sun never rises high enough to trigger Vitamin D3 synthesis in skin — regardless of sunny days. The NHS recommends all UK adults supplement during these months.
Immune system under more pressure
We spend more time indoors in winter, in closer contact with others, spreading viruses more easily. Cold, dry air also weakens the respiratory tract's natural defences.
Disrupted circadian rhythms
Shorter days shift melatonin production earlier, disrupting sleep patterns. This is compounded by artificial lighting and screen use.
Diet quality typically drops
Fresh fruit and vegetable consumption falls in British winter. Comfort food increases, nutrient density decreases. The nutrient gap widens.
Aligned with NHS guidance
The NHS recommends all UK adults consider taking Vitamin D3 10mcg (400 IU) daily from October to March.
Adults with dark skin, who cover their skin, or who spend little time outdoors may need to supplement year-round.
Omega-3 (EPA/DHA) is listed by UK government dietary guidelines as a nutrient most adults don't consume enough of.
Source: NHS England. Medibro is an independent retailer and is not affiliated with or endorsed by the NHS. This page is educational only — not medical advice.
The 3 winter stacks
Choose based on your main concern this winter. For best results, combine the immune stack with your choice of energy or sleep.
Immune defence
Most popular this seasonCold & flu season survival kit
Vitamin D3 4,000 IU
UK sun is insufficient Oct–Apr. D3 is the single most evidence-backed winter supplement.
Vitamin C 1,000mg
Reduces cold duration. Buffered form is gentler on the stomach.
Zinc Bisglycinate 25mg
Zinc lozenges shown to reduce cold symptoms by 33% in meta-analyses.
Winter energy
Trending NovemberBeat the seasonal slump
Vitamin D3 + K2
Low D3 is directly linked to winter fatigue and low mood (SAD). K2 ensures proper calcium metabolism.
B-Complex (all 8 Bs)
B vitamins fuel cellular energy production — depleted by stress and poor diet.
Iron Bisglycinate
Iron-deficiency anaemia is the most common nutritional deficiency in UK adults, particularly women.
Winter sleep
Editor's pickLonger nights, better rest
Magnesium Glycinate 400mg
Most UK adults are magnesium-deficient. Glycinate form crosses the blood-brain barrier to support deep sleep.
Ashwagandha KSM-66 300mg
Clinically shown to reduce cortisol by 28%, helping the nervous system down-regulate before bed.
L-Theanine 200mg
Creates calm alertness without drowsiness. Ideal with ashwagandha for anxious minds at bedtime.
Winter bestsellers
Our most-reviewed products — pharmacist-reviewed and lab-tested.
Lions Mane Mushroom 1000mg — Cognitive
★ 4.8
£24.99
NAD+ Precursor — NMN 500mg
★ 4.6
£49.99
Hyaluronic Acid 200mg — Joint & Skin
★ 4.5
£17.99
Calcium + D3 + K2 — Bone Density Triple
★ 4.7
£18.99
Joint Complex — Glucosamine, Chondroitin & MSM
★ 4.8
£21.99
Colostrum Powder 500mg — Gut & Immunity
★ 4.5
£29.99
Psyllium Husk Powder — 5g Fibre Per Serving
★ 4.5
£14.99
Digestive Enzyme Complex — 18 Enzymes
★ 4.5
£22.99
Not sure where to start?
Take our free 2-minute health score check. We'll identify your specific nutritional gaps and recommend exactly what to take this winter.
Food supplements are not medicines and are not intended to diagnose, treat, cure or prevent any disease. The NHS recommendation mentioned refers to Vitamin D3 supplementation. Always consult your GP before starting supplements, particularly if pregnant, breastfeeding, or on prescription medication.