During the autumn and winter months, people living in the UK are not exposed to strong enough UVB sun rays for the body to make enough of its own vitamin D naturally.

Our bodies make vitamin D when our skin is directly exposed to the sun – between April and September. However, as the days get colder and nights draw in, we’re making far less from October to April.

We require a sufficient level of vitamin D in the blood to support many bodily processes, which are important for bone health, muscle health, immune function, mental health and many others. Therefore, supplementing the natural vitamin D we make is essential from October to April.

Here, the Charity’s Health Improvement Lead Dr Greg Lessons reminds us of the importance of supplementing throughout the colder months, some key facts and figures, and ways of ensuring you supplement safely:

  • There are two forms of vitamin D: D2 (derived from plants) and D3 (derived from animals). D3 is more easily absorbed by the body
  • Sunblock will prevent UVB absorption, therefore it’s best to wait 20-30 minutes before applying any – ensuring you don’t burn in between. Your body will stop making vitamin D after this point, however, so it is then very important to apply sunblock to reduce risk of developing skin cancer
  • 10 micrograms of vitamin D per day is the recommended dosage for everyone in the UK from October through to March (including children and the elderly)
  • Being vitamin D deficient increases risk of infection. If you take 10 micrograms per day, you will have a sufficient blood level of vitamin D. If you were deficient, this dosage will get you above the minimum blood level within a month
  • Vitamin D is difficult to obtain from dietary sources in sufficient amounts, although it is present in oily fish, eggs and liver, therefore a supplement is often recommended
  • When taking supplements, check the label. The safe upper limit of supplemental vitamin D is 4000 IU. It can become toxic above this level, so ensure you only take the recommended amount
  • Taking the supplement with a meal containing a source of dietary fat can be beneficial, as it assists absorption
  • Black, Asian and minority ethnic groups may benefit from taking a vitamin D supplement every day (all year-round), as these population groups are at greater risk of deficiency