In addition to maintaining healthy bones, vitamin D can also reduce asthma attacks and help treat asthma in children and adults.

Vitamin D Reduces Asthma Attacks

Vitamin D Deficiency and Asthma

Vitamin D comes from a daily diet, such as fish and egg yolks. Vitamin D also comes from the photosynthetic of 7-Dehydrocholesterol (7-DHC)mechanism, spread in the skin. With exposure to sunlight, 7-DHC will turn into provitamin D3. Provitamin D3 further transforming into vitamin D3 through a heat-induced isomerization process. Vitamin D3 will undergo a hydroxylation process in the liver to become 25 (OH) D. Serum 25 (OH) D is the most widely circulating vitamin D metabolite in the blood and represents the amount of vitamin D in the blood that comes from food and synthesis in the skin.

Based on the Dietary Reference Intake issued by the Institute of Medicine (IOM) in 2011, that: serum 25 (OH) D <30nmol / L is expressed as a risk of vitamin D deficiency, <40nmol / L is expressed as an insufficient amount of vitamin D, and> 50nmol / L. However, a serum 25 (OH) D count <125 nmol / L is expressed as an adequate amount of vitamin D and is within safe limits. Vitamin D intake of 600 IU / day will keep serum 25 (OH) D levels in the range of 50nmol / L.

In 2011 in Qatar, a study examined the correlation between blood vitamin D levels and asthma in children. The study compared the serum 25 (OH) D levels of 671 children with asthma with 603 healthy children. The results of the study stated that 41.8% of children with asthma had moderate vitamin D deficiency (25 (OH) D serum levels of 25-47 nmol / L); this number was significantly greater than the control group, namely 25, 1% of children without asthma have moderate vitamin D deficiency. Also, 26.3% of the children with asthma had severe vitamin D deficiency (serum 25 (OH) D <25nmol / L), whereas only 11% of the children without asthma had severe vitamin D deficiency.

Another study in Costa Rica involving 287 children with asthma stated that people with asthma with insufficient vitamin D levels had a higher risk of asthma exacerbations than asthmatics with adequate vitamin D levels in the blood.

A study of 54 adults with asthma found associations between higher blood levels of vitamin D with: 
  1. better lung function
  2. reduced airway hyperresponsiveness, 
  3. and increased response to glucocorticoids (in vitro). 
These results suggest that vitamin D supplementation can reduce asthma severity and provide a better response to treatment when given in appropriate doses to asthmatics.

Vitamin D Supplementation for Asthma Treatment

A meta-analysis of seven randomized controlled trials involving 435 children and two randomized controlled trials involving 658 asthmatic adults stated that asthmatics who received vitamin D supplements experienced fewer asthma attacks requiring treatment with oral steroids. The average asthma attack per person in one year decreased from 0.44 to 0.28, with additional vitamin D intake. Vitamin D intake also reduced hospitalization risk for patients with acute asthma attacks from 6 per 100 to 3 per 100.

In all of the randomized controlled trials mentioned above, the control group's intervention was carried out in oral vitamin D3 (cholecalciferol). There was a difference in the dose of vitamin D given. Four randomized controlled trials used daily doses ranging from 500 IU / day - 1,200 IU / day. Another randomized controlled trial used a weekly dose, a monthly dose, a 2-month dose, or a bolus dose at baseline followed by a daily dose.

Based on a meta-analysis of nine randomized controlled trials, no increased risk of side effects was found with the vitamin D dose used in the randomized controlled trial. Giving vitamin D has no effect on lung function or daily asthma symptoms. More research is needed regarding the optimal dosage of vitamin D supplementation for asthma management.

Recommended Vitamin D Intake

Although the optimal dose of vitamin D supplementation has not been found for asthma management, it is important to note the amount of vitamin D intake per day. Vitamin D is naturally found in everyday foods such as fish (tuna and salmon), cheese, egg yolks, and foods fortified with vitamin D such as cereal, packaged orange juice, or oatmeal. To get sufficient vitamin D intake per day, one of the foods consumed is 170 grams of salmon (containing 600 IU of vitamin D or the equivalent of 15 mcg). High doses of vitamin D can also be obtained in vitamin D supplements. The Upper Intake Level of vitamin D applicable in America (issued by the Food and Nutrition Board) and Europe (issued by the European Commission Scientific Committee on Food) is 2000 IU / day.

Side Effects of Long-Term High Doses of Vitamin D

Very high blood levels of vitamin D resulting from too high a dose of vitamin D can cause nausea, vomiting, decreased appetite, abdominal pain, constipation, or diarrhea. It can also cause prolonged fatigue, nausea, vomiting, and slurred speech. Excess vitamin D will increase the calcium level in the blood (hypercalcemia), causing indigestion, dizziness, excessive thirst, and frequent urination.