The exact dose of vitamin D that increases the risk for heart and kidneys

The exact dose of vitamin D that increases the risk for heart and kidneys

Medical Advice

Express newspaper
23/02/2026 19:51

A doctor has warned about the dangers of taking too much vitamin D, urging people to stick to the recommended doses. Dr Oscar Duke appeared on BBC Morning Live to explain the health consequences of taking too much.

According to the NHS, vitamin D is essential for regulating calcium and phosphorus in the body, which are key elements for healthy bones, teeth and muscles. It also plays an important role in strengthening the immune system.

However, due to the climate in the UK, many people fail to get enough vitamin D from sunlight. For this reason, supplementation is particularly recommended during the autumn and winter. “It is especially important to take extra vitamin D during these months, because the sun does not provide us with enough of it,” explained Dr Duke.

But he warns that too much can have serious consequences. The NHS and UK government’s recommendation is that adults and children over the age of one should take 10 micrograms a day, equivalent to 400 international units (IU), from October to early March.

The problem, according to the doctor, is that overdose can happen more easily than you think, as many over-the-counter supplements contain 800–1.000 IU per tablet. “If you take over 4.000 IU per day, you risk vitamin D overdose,” Dr. Duke stressed.

The NHS warns that taking high amounts over long periods can lead to a build-up of calcium in the blood, a condition known as hypercalcaemia, which is linked to serious health problems including heart disorders and kidney stones.

Although vitamin D toxicity is considered rare, the Food Standards Agency recommends that 4.000 IU (100 micrograms) per day is the maximum safe limit for adults.

On the other hand, vitamin D deficiency remains widespread: government data shows that around one in six adults in Britain have insufficient levels during the winter, according to the National Diet and Nutrition Survey.

Dr. Oscar Duke’s message is clear: the benefits of vitamin D are obtained only when the recommended doses are respected. Exceeding the safe limit can have serious health consequences. Therefore, always check the labels of supplements and consult your doctor if you are unclear about the amount you are taking. /GazetaExpress/