Many people with multiple sclerosis (MS) 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 nutrient may be beneficial for people who already have MS by reducing the severity of symptoms and lengthening the time that it takes to move from relapsing to progressive MS. But, without monitoring the vitamin’s use, it can be harmful.
Vitamin D overdose
The Irish Medical Journal reported about a man with MS and the story demonstrated the risks associated with overconsumption of 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 was safe. However, the duration of the pilot study was only six months. The man in the above case 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 — no more than 4,000 IU a day.
If someone is diagnosed with a vitamin D deficiency, a weekly dose of 50,000 IU 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 problems arise due to the wide availability of vitamin supplements. Walk into any pharmacy and you will see vitamin D products of varying strengths sitting on the shelves.
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.