News, info and tips for living with multiple sclerosis

Overdosing on Vitamin D Supplements? It’s possible.

Overdosing on Vitamin D Supplements? It’s possible.

Many people with multiple sclerosis use vitamin D supplements. I’ve been popping a 2,000 IU tablet of vitamin D3 each morning for many years. And with good reason.

Studies show that having an adequate blood level of vitamin D may lower a person’s risk of developing MS. Research also indicates the vitamin may reduce the severity of MS symptoms and lengthen the time that it takes to move from relapsing to progressive MS. But, in some cases using vitamin D can also be harmful.

Vitamin D supplement overdose

The Irish Medical Journal has a report about a man with MS that demonstrates the risks associated with taking too much vitamin D. The man, who was 45 years old and restricted to a wheelchair because of his MS, had been vomiting, constipated, and lethargic for over a week. In the emergency room, blood tests revealed that he had severe hypercalcemia — in layman’s terms, too much calcium — as well as an acute kidney injury.

A small study in 2016 found that a daily dose of vitamin D3 as high as 10,400 IU is safe. However, that study only tracked vitamin D users for six months. The man in Ireland had been taking roughly that amount of the vitamin — but for almost two years! He told doctors he hadn’t seen a neurologist in seven years.

How much vitamin D is too much?

A neurologist responding to a patient’s question on the Mayo Clinic’s website stated that The Institute of Medicine (now the National Academy of Medicine) recommends 600 IU a day for adults up to age 70 and 800 IU a day for those 71 and older — but, no more than 4,000 IU a day.

If someone is diagnosed with a vitamin D deficiency, a dose of 50,000 IU a week, for up to three months, is recommended until levels normalize. Afterward, a maintenance dose of between 2,000 and 5,000 IU a day is advised.

Talk it over with your neuro

The Irish Medical Journal article reports, “There is increasing evidence to support a beneficial effect of vitamin D on the inflammatory component of MS, and correction of vitamin D insufficiency in MS patients is recommended.” But a wide variety of vitamin D supplements are easily available. Walk into most any pharmacy and you’ll see dozens of products of varying strengths sitting on the shelves. People tend to use them without medical guidance. That can be a problem.

In her presentation at ACTRIMS Forum 2017, neurologist Ellen Mowry of Johns Hopkins MS Center in Baltimore said, “I tell my patients that Vitamin D is also a medication and even though it is available over the counter you still need to be followed by the doctor.” She suggested a daily dose of 5,000 IU for the “average” person with MS.

The bottom line is that a lot of evidence shows that vitamin D, whether derived naturally from sunlight or artificially in from tablet, can be beneficial to someone with MS. But don’t use it like the guy in Ireland did. If you’re considering a vitamin D supplement, or you’re already taking one, talk it over with your physician.

(A version of this post first appeared as my column on the Multiple Sclerosis News Today website).

(Featured image from PublicDomainPictures from Pixabay).