Vitamin D's effect on asthma, pneumonia, depression, panic disorders and bone health*
More vitamin D, less asthma
Doctors said there are few studies on the effect of vitamin D on asthma severity in adults. In this trial, researchers separated 121 asthmatic adults into five groups based on levels of circulating vitamin D. Those whose vitamin D levels fell below 30 ng/mL were five times more likely to have severe asthma as were those whose vitamin D levels were 30 ng/mL or more. Researchers also found that, for every 1 ng/mL increase in circulating vitamin D, chances of being hospitalized or seeking emergency treatment for asthma declined by 10 percent. Discussing their findings, doctors said vitamin D activates the immune anti-microbial response and helps reduce air-passageway inflammation and sensitivity to asthma triggers such as cold weather, dust, and smoke, easing symptoms and improving respiratory health. Vitamin D reduces pneumonia
Recent studies have highlighted a link between low levels of vitamin D and pneumonia in older adults living independently. In this study, doctors measured vitamin D levels in 16,974 people, at least age 17, and compared their histories of pneumonia. After adjusting for seasonal differences, body mass index scores, smoking, lung, heart and other chronic diseases, researchers found that those with vitamin D levels below 30 nanograms per milliliter of blood (ng/mL) were 56 percent more likely to develop pneumonia compared to those whose vitamin D levels were 30 ng/mL or more. Doctors said that the optimal range may begin at 30 ng/mL rather than at 20 ng/mL for vitamin D. Low vitamin D levels linked to depression and panic disorders
There is some study evidence of a link between low levels of vitamin D and chances for depression and phobia in middle-aged adults. In this study, doctors followed 5,966 participants from childhood to age 50. At age 45, researchers measured vitamin D levels while nurses surveyed mental health. Compared to those whose vitamin D levels were less than 10 nanograms per milliliter of blood (ng/mL), those with vitamin D levels greater than 30 ng/mL were 43 percent less likely to develop depression and 67 percent less likely to have panic disorder. Those who were more physically active, were not obese, did not smoke heavily, or who avoided watching TV or using a computer for more than three hours per day, were most likely to have the best mental health. Calcium and vitamin D may extend life in women
Doctors recommend calcium and vitamin D for bone health, but the effect of calcium on heart health is unclear. In this study, researchers measured the diets of 9,033 men and women and followed up for 10 years. While there was no effect in men, women who took calcium supplements were 22 percent less likely to have died than women who did not take calcium supplements. Compared to women who didn’t take calcium, women who took calcium in doses up to 1,000 mg per day were 21 percent less likely to die prematurely. Compared to women who took neither calcium nor vitamin D, women who took both calcium with vitamin D reduced their chances of dying prematurely by 23 percent. Vitamin D improves bone health
Doctors wanted to test the effects of different doses of vitamin D on bone mineral density. In this study, 265 postmenopausal women aged 60 to 70 took a placebo, 400 IU, or 1,000 IU of vitamin D per day. After one year, vitamin D levels had declined by 11 percent for placebo, increased 94 percent in the low-dose vitamin D group, and increased 129 percent in the high-dose vitamin D group.
Only the high-dose vitamin D group saw a benefit in bone mineral density, which declined by 0.05 percent, compared to 0.57 for the low-dose vitamin D group and 0.60 for placebo. One month after the study ended, vitamin D levels continued to decline in all groups, but remained in the normal range for those who had taken vitamin D. Vitamin D strengthens bones in girls
Doctors in this study measured bone health in 167 adolescent girls and 171 boys who took a weekly placebo, 14,000 IU of vitamin D per week, or 1,400 IU of vitamin D per week. After one year, there was no significant effect in boys. In girls, those who took the placebo had a 4.2 percent increase in bone mass of the hip, a 6.8 percent increase in the high-dose group, and a 7.9 percent increase in bone mass for the low-dose vitamin D group. One critical measure of the balance between bone thickness and width, called the buckling ratio, at the narrow part of the neck of the femur bone, strengthened in girls by 1.9 percent for placebo, by 2.4 percent in the high-dose group, and by 6.1 percent in the low-dose vitamin D group.