London, England — A general practitioner is advising individuals considering vitamin D supplements to first undergo a blood test to assess their levels, warning that excessive intake may lead to serious health issues. In a widely viewed video, Dr. Asif Ahmed highlighted the alarming trend of people consuming dangerously high doses of vitamin D, which can lead to complications such as abnormal heart rhythms, kidney failure, and bone pain.
Approximately one in six adults in the United Kingdom is estimated to have insufficient vitamin D levels, according to Dr. Ahmed. He cautioned that while some are not getting enough of this essential nutrient, others are overindulging. Commonly referred to as the “sunshine vitamin,” vitamin D is primarily obtained from sunlight, though it is also present in foods like oily fish, red meat, and egg yolks.
NHS guidelines recommend vitamin D supplementation, especially during the winter months when sunlight exposure decreases. However, Dr. Ahmed emphasized the dangers of high long-term doses, stating that excessive vitamin D can lead to hypercalcemia—a condition caused by elevated calcium levels in the blood, which increases the risk of heart and kidney disease.
Unlike many supplements that are expelled through urine, vitamin D is fat-soluble and can accumulate in the body, leading to harmful effects. “When you consume excessive amounts of fat-soluble vitamins like vitamin D, they are not easily removed from the body,” he explained. “This accumulation can weaken bones and damage vital organs.”
Dr. Ahmed reported seeing individuals taking alarmingly high doses—up to 10,000 international units—far exceeding the NHS recommendation of no more than 4,000 units per day for adults, including pregnant and breastfeeding women, seniors, and adolescents aged 11 to 17. He noted that the typical requirement for most adults is around 10 micrograms, or 400 units.
The vitamin plays a critical role in maintaining healthy bones, teeth, and muscles by regulating calcium and phosphate levels. While Dr. Ahmed acknowledged that some individuals might need higher doses based on specific health conditions, he reiterated the importance of monitoring vitamin D levels through regular blood tests. In the U.S., the recommended minimum threshold for vitamin D is set at 20 ng/ml, significantly higher than the UK’s threshold of 12 ng/ml, which has drawn criticism from international health experts.
Factors such as ethnic background, skin color, and individual symptoms can influence vitamin D needs. “The correct dosage really depends on several personal factors, which is why a blood test is crucial,” Dr. Ahmed said. He urged those supplementing with vitamin D to exercise caution and prioritize responsible use.
Dr. Ahmed is not alone in his warning. NHS surgeon Dr. Karan Rajan has also recommended looking for vitamin D supplements containing vitamin K2, which may help mitigate the risk of calcium buildup in the bloodstream.
While supplements have their place, health experts advocate for obtaining vitamin D through adequate sunlight exposure and a balanced diet rich in foods like oily fish, red meat, and fortified products to ensure optimal health without the risks associated with excessive supplementation.