Guess I am predisposed to getting into a low mood over winter and should book a holiday or some ladies before the food and drink take over next time.
Could be a vitamin D deficiency
A deficiency in Vitamin D can show up in many ways, and the signs are often subtle at first.
Common symptoms include:
😴 Fatigue & Low Energy* Persistent tiredness or feeling drained
* Poor sleep or non-restorative sleep
🦴 Bone & Muscle Problems* Bone pain or tenderness
* Muscle aches, weakness, or cramps
* Increased risk of fractures due to reduced calcium absorption
🧠 Mood & Cognitive Effects* Low mood or depressive symptoms (linked to Depression (mood disorder))
* Brain fog or difficulty concentrating
🛡️ Immune System Issues* Getting sick more often (frequent colds or infections)
* Slower recovery from illness
🩸 Severe or Long-Term Deficiency Can Lead To:* Rickets in children (soft or weak bones)
* Osteomalacia in adults (bone pain, muscle weakness)
👀 Less Obvious Signs* Hair thinning or shedding
* Low mood or irritability
* Slow wound healing
📌 Important to KnowMany people with low vitamin D have **no obvious symptoms** until levels become quite low, which is why testing is often needed to detect a deficiency.
The exact percentage depends on **how “deficiency” is defined** and the time of year, but here are the most reliable UK estimates:
🇬🇧 Overall UK population* About **16% of adults** are considered *vitamin D deficient* (below 25 nmol/L) on average across the year
* In **winter (Jan–March)**, this rises to around **29% of adults**
📊 Broader picture (including “low” levels, not just deficiency)* Around **50% of UK adults have “below optimal” vitamin D levels** (not necessarily clinically deficient, but still low)
👥 Important differences* Some groups have much higher rates:
* Up to **50–57%** in certain ethnic minority groups during winter
* Around **12–17%** in white populations depending on season
🧠 Simple takeaway* **~1 in 6 UK adults** are deficient year-round
* **~1 in 3 in winter**
* **Up to half** have *suboptimal* (low) levels
Your body gets Vitamin D in **three main ways**:
☀️ 1. Sunlight (the main source)When sunlight hits your skin, your body produces vitamin D naturally. This happens when **UVB rays** from the sun trigger vitamin D production in your skin.
Key points:
* Short periods of sun on **bare skin** (arms/face) can be enough in summer
* Glass blocks UVB, so you **don’t** make vitamin D through windows
* In the UK, sunlight is often too weak between **October and March** for effective production
🍽️ 2. Food (smaller but important source)Only a few foods naturally contain vitamin D, such as:
* Oily fish (e.g. Salmon, Mackerel, Sardine)
* Egg yolks
* Red meat
* Fortified foods (some milks, cereals, plant milks)
💊 3. SupplementsMany people in the UK rely on supplements, especially during winter or if they:
* Spend little time outdoors
* Have darker skin
* Wear clothing that covers most of the skin
* Are older or housebound
🧠 Important noteDiet alone usually **isn’t enough** for most people to maintain healthy vitamin D levels — sunlight or supplements are often needed.
