Overdosing on vitamin D is possible, doctors have warned, after a British man was hospitalised for taking megadoses of supplements, including vitamin D.
The case study in the journal BMJ Case Reports is not the first time experts have cautioned against overusing the “sunshine supplement”. In 2019, a three-year Canadian study found that too much of it could actually decrease bone density.
In the most recent case, reports News24, a middle-aged man started taking more than 20 over-the-counter supplements daily, including 50 000 international units (IU) of vitamin D three times a day.
The dosage was considerably higher than standard nutritional recommendations, the doctors wrote.
A month later, he suffered various symptoms, including nausea, abdominal pain, tinnitus (ringing in the ears), leg cramps, diarrhoea, increased thirst, and recurrent vomiting for nearly three months before he sought medical attention. Although he stopped taking his daily supplement cocktail, his symptoms remained.
“Compared with studies among the general population, nutritional supplement misuse or abuse has been extensively documented and reviewed among athletes (but) the present case describes the misuse of supplements with more than 20 active agents in a middle-aged man, who was not a professional athlete, with resultant vitamin D intoxication and hypercalcaemia,” the authors wrote.
Hypercalcaemia is a condition involving abnormal calcium levels in your blood, and this can weaken your bones and affect heart and brain function.
Rise in supplement overdoses
Concerningly, overdosage of vitamin D, formerly known as “hypervitaminosis D”, is on the rise and linked to a various potentially serious health issues.
“Globally, there is a growing trend of hypervitaminosis D, a clinical condition characterised by elevated serum vitamin D3 levels, with women, children and surgical patients most likely to be affected,” the authors wrote.
Last month, experts from a separate study stressed that unless a person had a real deficiency or was pregnant, there was no benefit to taking vitamin and mineral supplements. In fact, they pointed to evidence that some popular supplements could do more harm than good.
Current case report
The results of the man’s blood tests showed very high levels of calcium as well as slightly raised magnesium levels. His vitamin D level was also seven times over the level required for sufficiency. Moreover, the tests showed that his kidneys weren’t functioning properly.
He was hospitalised for eight days and received intravenous fluids to flush out his system. He was also treated with bisphosphonates – drugs used to strengthen bones or lower excessive levels of calcium in the blood.
While his calcium level had returned to normal two months after being discharged from hospital, his vitamin D level was still abnormally high.
“Given its slow turnover (half-life of approximately two months), during which vitamin D toxicity develops, symptoms can last for several weeks,” warned the authors.
Consult a doctor before taking supplements
Dr Alamin Alkundi, co-author of the report, and an endocrinologist at William Harvey Hospital in the UK, advised people to seek their doctor's opinion regarding any alternative therapy or over-the-counter medications they wanted to take.
“This case report further highlights the potential toxicity of supplements that are largely considered safe until taken in unsafe amounts or unsafe combinations,” the authors of the report said.
Study 1 details
Vitamin D intoxication and severe hypercalcaemia complicating nutritional supplements misuse
Alamin Alkundi, Rabiu Momoh, Abdelmajid Musa and Nkemjika Nwafor.
Published in BMJ Case Studies June 2022
Patients often pursue unconventional or alternative therapy, the health outcomes of which remain controversial. An example is the use of over-the-counter nutritional supplements. Data on hypervitaminosis D or vitamin D toxicity are limited. This case report aims to contribute to the body of knowledge regarding this topic, which is of public health importance. Considering this topic, issues such as the potential interaction of over-the-counter and prescribed medications, market regulations of nutritional supplements, the misuse of these supplements in sports, and the potential harm among unsuspecting population groups (eg, children and the elderly) remain matters of public health significance that need to be addressed.
This case report discusses an uncommon presentation of vitamin D intoxication and severe hypercalcaemia attributed to misuse of multiple nutritional supplements (˃20 active agents). A review of this case, supported by accumulated literature, lends room to further public health safety discussions. The multisystemic clinical manifestations of vitamin D toxicity can be debilitating, hence the need to prevent its occurrence.
Study 2 details
Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and CancerUS Preventive Services Task Force Recommendation Statement
US Preventive Services Task Force
Published in JAMA Network on 21 June 2022
According to National Health and Nutrition Examination Survey data, 52% of surveyed US adults reported using at least 1 dietary supplement in the prior 30 days and 31% reported using a multivitamin-mineral supplement. The most commonly cited reason for using supplements is for overall health and wellness and to fill nutrient gaps in the diet. Cardiovascular disease and cancer are the 2 leading causes of death and combined account for approximately half of all deaths in the US annually. Inflammation and oxidative stress have been shown to have a role in both cardiovascular disease and cancer, and dietary supplements may have anti-inflammatory and antioxidative effects.
To update its 2014 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a review of the evidence on the efficacy of supplementation with single nutrients, functionally related nutrient pairs, or multivitamins for reducing the risk of cardiovascular disease, cancer, and mortality in the general adult population, as well as the harms of supplementation.
Community-dwelling, nonpregnant adults.
The USPSTF concludes with moderate certainty that the harms of beta carotene supplementation outweigh the benefits for the prevention of cardiovascular disease or cancer. The USPSTF also concludes with moderate certainty that there is no net benefit of supplementation with vitamin E for the prevention of cardiovascular disease or cancer. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with multivitamins for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with single or paired nutrients (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined.
The USPSTF recommends against the use of beta carotene or vitamin E supplements for the prevention of cardiovascular disease or cancer. (D recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamin supplements for the prevention of cardiovascular disease or cancer. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of single- or paired-nutrient supplements (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer.
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