How to get enough vitamin D in the winter

As the days grow shorter and temperatures drop, our exposure to sunlight naturally decreases, leading to a reduction in our body's ability to produce vitamin D. This essential nutrient, often referred to as the "sunshine vitamin," plays a critical role in maintaining overall health.

Vitamin D helps regulate the absorption of calcium and phosphorus, supports the immune system, and is crucial for maintaining healthy bones and muscles¹. During the winter months, ensuring adequate vitamin D intake becomes particularly important, especially for individuals living in regions with limited sunlight such as the UK.

Why is vitamin D important?

Vitamin D is vital for a range of bodily functions. Primarily, it helps regulate calcium and phosphate in the body, which are necessary for healthy bones, teeth, and muscles. Deficiency in vitamin D can lead to bone deformities, such as rickets in children, and bone pain caused by a condition called osteomalacia in adults. Additionally, there is growing evidence that vitamin D plays a role in modulating the immune system, reducing the risk of chronic diseases, and potentially lowering the risk of respiratory infections, which are more prevalent in the winter months².

During winter, the angle of the sun's rays means that ultraviolet B (UVB) radiation, which is necessary for skin synthesis of vitamin D, is often insufficient. This limited exposure to sunlight can lead to low levels of vitamin D, necessitating a focus on alternative sources to maintain adequate levels.

Health risks of vitamin D deficiency

Vitamin D deficiency can lead to problems with your bones. In adults, it can increase your chance of developing problems such as osteopenia or osteoporosis where your bones are weaker. It can also lead to bone and muscle pain and a condition called osteomalacia. In children vitamin D deficiency can lead to a condition known as rickets, which can lead to deformity of bones³.

There is ongoing research looking at the role of Vitamin D in relation to conditions such as neurological disorders (e.g. Multiple sclerosis), cancer, heart disease and diabetes however more work is required to establish if there is any significance to this⁴.

Practical tips for maintaining adequate vitamin D levels in winter

To maintain adequate vitamin D levels during the winter months, consider the following strategies:

Increase dietary intake

Consuming foods rich in vitamin D is one of the most effective ways to ensure adequate intake. Foods such as oily fish (salmon, mackerel, and sardines), red meat, liver, egg yolks, and fortified foods like margarine, cereals, and dairy products can help provide a daily dose of vitamin D. The NHS recommends that people include vitamin D-rich foods in their diet regularly to help maintain adequate levels⁵.

Consider vitamin D supplements

The NHS advises that everyone, especially during autumn and winter, consider taking a daily vitamin D supplement. The recommended daily dose for adults is 10 micrograms (400 IU) of vitamin D per day to help keep bones and muscles healthy⁶. This is particularly important for individuals who may not be able to get sufficient vitamin D from sunlight exposure or diet alone, such as older adults, pregnant or breastfeeding women, people with darker skin, or those who cover their skin for cultural reasons, who may be advised to take a supplement all year round.

Make the most of daylight

Even in winter, try to spend some time outdoors when the sun is out, especially during midday when UVB rays are most potent. Aim for at least 10 to 30 minutes of sun exposure several times a week on uncovered skin such as the face, arms, or legs. However, balance this with skin cancer risk and avoid sunburn.

Monitor your vitamin D levels

Regular check-ups with your healthcare provider can help monitor your vitamin D levels, especially if you are at risk of deficiency. Blood tests can determine if you need to adjust your diet or supplement intake. MyHealthChecked offer a Vitamins & Minerals Blood Test which allows you to check on your full vitamin panel. MyHealthChecked’s Vitamin D Rapid Test offers a quick way of screening your levels at home with results in 20 minutes. MyHealthChecked’s Vitamins & Minerals DNA Test will allow you to explore if a deficiency is in your genes and whether you will need to always keep a closer eye on your nutrition.

References

1. Holick MF. (2007). Vitamin D deficiency. New England Journal of Medicine, 357(3), 266-281.
2. Martineau AR, Jolliffe DA, Hooper RL, et al. (2017). Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of individual participant data. BMJ, 356, i6583.
3. BMJ Best Practice (2024). Vitamin D deficiency. [Available at https://bestpractice.bmj.com/topics/en-gb/641]
4. Wang H, Chen W, Li D, et al. (2017). Vitamin D and Chronic Diseases. Aging Dis. 2017 May 2;8(3):346-353.
5. NHS. (2022). Vitamin D. [Available at: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/]
6. NICE CKS. (2018). Vitamin D deficiency in adults - treatment and prevention. [Available at: https://cks.nice.org.uk/topics/vitamin-d-deficiency-in-adults-treatment-prevention/]