When and why you should take Vitamin D, as man dies from overdose

Woman taking vitamin D tablet. (Getty Images)
Make sure you're getting the right amount of vitamin D this autumn and winter. (Getty Images)

Vitamin D is one of the most important vitamins for our health, with benefits including calcium regulation and maintaining strong bones.

In the darker months, vitamin D - often dubbed the sunshine vitamin - can be hard to get, with research showing that a third of Brits have low levels of it.

However, extremely high doses of vitamin D can also be dangerous and even fatal. It has been reported that an 89-year-old man from Oxted, Surrey, died from an "overdose" of vitamin D supplements.

David Mitchener's death was reportedly attributed to hypercalcaemia, a build-up of calcium in the body as a result of taking too much vitamin D. Following the incident, the Surrey assistant coroner has called on regulatory bodies to make it mandatory for supplement packaging to include warnings about the dangers of overconsumption.

On the other hand, inadequate vitamin D levels can contribute to a range of health issues. That's why it's important to be aware of the signs that you might not be getting enough, and when and why you might want to consider taking supplements.

Signs of vitamin D deficiency

Wellness expert Samantha Greener from Simply Supplements says many people are unknowingly deficient in this essential nutrient because some of the symptoms can be easily overlooked or attributed to a busy lifestyle, which can potentially mask underlying, more significant health concerns.

Greener says some of the signs of vitamin D deficiency include:


Feeling unusually tired or lethargic can be an early sign of a vitamin D deficiency.

Bone and lower back pain

Vitamin D is closely linked to calcium absorption and its deficiency can weaken bones. This can result in bone pain, especially in weight-bearing bones like the spine.

Muscle aches

Vitamin D is essential for optimal muscle function as it plays an important role in regulating muscle contraction and relaxation, ensuring that muscles operate efficiently and without unnecessary strain. Additionally, a deficiency in vitamin D is linked to increased inflammation, contributing to muscle pain and aches.

Frequent illness

Vitamin D is crucial for supporting the immune system and helping your body ward off illnesses, such as colds, infections and the flu.

Hair loss

Insufficient vitamin D levels can play a role in hair loss. This is because inadequate vitamin D can disrupt the normal function of keratinocytes, disturbing the natural hair growth cycle. This can result in reduced hair growth and increased shedding.

Impaired wound healing

Vitamin D helps your body repair and regenerate tissue. If you get a wound and it takes longer than usual to heal, your vitamin D levels may be too low.

Woman soaking up sunlight. (Getty Images)
While it's good for your body to make vitamin D from sunlight, still take measures to protect your skin in warmer months. (Getty Images)

Sources of vitamin D

We can get vitamin D from natural sources, including sunlight in the right months. It's also found in a small number of foods including:

  • oily fish (like salmon, sardines, herring and mackerel)

  • red meat

  • liver

  • egg yolks

  • fortified foods – (like some fat spreads and breakfast cereals)

Why and when should I take vitamin D supplements?

As well as boosting our brain and immune system and promoting healthy bones and teeth, dietitian Christina Jax, from healthy eating app Lifesum says having sufficient levels of vitamin D may also protect against a range of chronic diseases, infections and conditions, including type 1 diabetes and heart disease.

The government advises that everyone should consider taking a daily vitamin D supplement during the autumn and winter.

"When outdoors, the body creates vitamin D from direct sunlight on the skin. The majority of people make all the vitamin D they need from sunlight, typically between early April until late September," says Jax.

"But in autumn and winter, typically between October and March, we don’t make enough vitamin D from sunlight alone."

This means in the colder months you need to lean more on your diet, but as it's hard to get the needed amount from food alone, the NHS advises that adults and children over four (including pregnant and breastfeeding women) should consider taking a supplement every day of 10 micrograms of vitamin D during autumn and winter.

People at high risk of not getting enough vitamin D, which is all children aged one to four, and all babies (unless they're having more than 500ml of infant formula a day) should take a daily supplement throughout the year.

The Department of Health and Social Care also advises adults and children over four take a daily 10 microgram supplement throughout the year if they:

  • aren't outdoors much (they're frail, or housebound)

  • are in an institution like a care home

  • usually wear clothes that cover up most of their skin when outdoors

You can take vitamin D in the form of supplements or drops (for under fives), available at most pharmacies and supermarkets, but women and children who qualify for the Healthy Start scheme get free vitamin D supplements.

Man speaking to doctor. (Getty Images)
Speak to a doctor first and prevent yourself from taking too much vitamin D. (Getty Images)

It is also worth being aware of not taking too much vitamin D, as this can cause too much calcium to build up in the body (called hypercalcaemia), potentially weakening bones and damaging the kidneys and heart.

Always speak to your doctor before taking supplements to find out whether you need them, the right amount for you, and whether it's safe for you to take them.

The NHS website also states: "There have been some reports about vitamin D reducing the risk of coronavirus (COVID-19). But there is currently not enough evidence to support taking vitamin D solely to prevent or treat COVID-19."

Watch: Low vitamin D levels linked to inflammation