Two different studies suggest the benefits, and risks, of taking Vitamin D among specific groups of people.

One study suggests that, in people with multiple sclerosis (MS), high doses of Vitamin D3 may help regulate the body’s hyperactive immune response. However, a different study suggests that, in patients 70 and older, high monthly doses of Vitamin D had no benefit on low-extremity function but reportedly led to a higher risk of falls.

The study among MS patients was conducted by Johns Hopkins researchers and was published recently online in Neurology, the medical journal of the American Academy of Neurology, per a release from Johns Hopkins Medicine.

In the study, researchers gave 40 people with relapsing-remitting MS either 10,400 international units or 800 international units of vitamin D3 supplements per day for 6 months. Patients with severe vitamin D deficiency were not included in the study. The current recommended daily allowance of vitamin D3 is 600 international units. The team performed blood tests at the start of the study and again at 3 and 6 months to measure the amount of vitamin D in the blood and the response in the immune system’s T cells, which play a key role in MS, the release explains.

The people taking the high dose had a reduction in the percentage of inflammatory T cells related to MS severity, specifically IL-17+CD4+ and CD161+CD4+ cells. When the increase in vitamin D levels in the blood over base line levels was greater than 18 ng/mL, every additional 5 ng/mL increase in vitamin D led to a 1% decrease in the percentage of IL-17+CD4+ T cells in the blood. The people taking the low dose did not have any noticeable changes in the percentages of their T cell subsets, the release continues.

Heike A. Bischoff-Ferrari, MD, DrPH, of the University Hospital Zurich, Switzerland, and coauthors conducted the second study. The 1-year, randomized clinical trial included 200 men and women 70 or older with a prior fall, per a release from The JAMA Network Journals.

Participants were divided into three study groups: 67 people in a low-dose control group who received 24,000 IU of vitamin D3 per month; 67 people who received 60,000 IU of vitamin D3 per month; and 66 people who received 24,000 IU of vitamin D3 plus calcifediol per month. The study measured improvement in lower-extremity function, achieving 25-hydroxyvitamin D levels of at least 30 ng/mL at 6 and 12 months, and reported falls, the release explains.

The researchers found that, among the participants, 58% were vitamin D deficient at baseline, and 60.5% (121 of 200) experienced a fall during the 12-month treatment period.

They also found that doses of 60,000 IU and 24,000 IU plus calcifediol were more likely to result in 25-hydroxyvitamin D levels of at least 30 ng/mL but they were associated with no benefit on lower-extremity function.

Regarding fall percentages, the researchers found that the 60,000 IU and 24,000 IU plus calcifediol groups had higher percentages of participants who fell (66.9% and 66.1%, respectively) compared with the 24,000 IU group (47.9%).

And finally, the 60,000 IU and 24,000 IU plus calcifediol groups had a higher average number of falls (1.47 and 1.24, respectively) compared with the 24,000 IU group (0.94), the release explains.

The study was published recently online by JAMA Internal Medicine.

[Source(s): Johns Hopkins Medicine, The JAMA Network Journals, Science Daily]