Overview
- UK health guidance still recommends a daily 10 microgram vitamin D supplement from October to March, according to the NHS.
- Clinicians warn that taking more than recommended can lead to toxicity, with reported side effects including headaches, skin reactions, stomach pain, nausea and raised calcium levels, and they advise speaking to a doctor if these occur.
- Telltale signs after increasing intake or adding sprays or gummies include constant thirst with frequent urination, queasiness or tummy pain or constipation, headaches or brain fog, and new aches or cramps, and experts advise stopping supplements and reassessing if these appear.
- Consumer testing has reported some vitamin D products at doses far above safety limits, in some cases up to about 12.5 times higher, prompting advice to check label strength and avoid duplication across tablets, multivitamins, sprays, gummies and fortified foods.
- Practical guidance stresses choosing a single simple D3 product at 10 micrograms, taking it with a meal if sensitive, and maintaining vigilance given widespread use, with one report citing 42% of UK adults having taken vitamin D in the past year.