Man dies after consuming too much vitamin D as experts warn of risks: 'Cascade of problems'

Vitamin D helps build strong bones by promoting the absorption of calcium.

Amid reports of a U.K. man's death from high amounts of vitamin D, experts are warning about the dangers of unsafe levels.

After 89-year-old David Mitchener died last year from hypercalcemia, a buildup of calcium in the body that is caused by excess levels of vitamin D, the Surrey assistant coroner released a report urging regulatory agencies to warn consumers about the risk of excessive intake.

Michener was admitted to East Surrey Hospital on May 10, 2023, and died 10 days later. Tests revealed that his vitamin D levels were at the maximum recordable level, according to the report from Jonathan Stevens, the assistant coroner.

Vitamin D toxicity was listed as one of the factors in Michener’s death, along with congestive heart failure, ischemic heart disease, chronic kidney failure and hypercalcemia.

"David Mitchener had been taking vitamin supplements for at least the preceding nine months," the report stated.

The supplements he was taking did not have any warnings on or in the packaging detailing the specific risks or side effects, according to the report.

"Vitamin supplements can have potentially very serious risks and side effects when taken in excess," Stevens wrote.

"Current food labeling requirements do not require these risks and side effects to be written on the packaging."

What is a safe level of vitamin D?

For healthy adults, 600 international units (IU) of vitamin D (15 mcg) per day is all that's necessary, according to Pieter Cohen, associate professor of medicine at the Cambridge Health Alliance in Massachusetts.

"Usually, this can come from fortified foods and sunlight," he told Fox News Digital.

Some foods that are high in vitamin D include orange juice, rainbow trout, salmon, portabella mushrooms, yogurt, tuna and milk, according to WebMD.

Healthy people should not be taking more than 4,000 IU (100 mcg) per day, Cohen advised.  

"Taking more than that can cause a cascade of problems, as vitamin D acts as a hormone in the body and too much of it can lead to a number of issues," he warned.

"Overdosages occur with taking much more — usually 60,000 international units a day or more."

The amount of vitamin D required in the diet can also vary by age, according to Dr. Maryann Amirshahi, professor of emergency medicine at Georgetown University and co-medical director of the National Capital Poison Center in Washington, D.C.

"Smaller amounts (400 IU) are recommended in the first year of life," she told Fox News Digital.

"For children older than 1 year of age, adolescents and most adults, 600 IU a day is recommended. The dose is the same for people who are pregnant or lactating."

For older adults over age 70, an intake of 800 IU per day is recommended.