A “normal” intake of vitamin D can reduce the risk of death substantially in people with cardiovascular disease, a Norwegian study has suggested.
Researchers from the University of Bergen concluded that patients with cardiovascular disease and a normal intake of vitamin D reduced their risk of morality as a consequence of the disease by 30%. However, two little or too much of the vitamin had a detrimental effect on risk, they said.
“Fish and cod liver oil are important sources to vitamin D during the winter”
The study followed as many as 4,000 patients with cardiovascular diseases from year 2000, for a period of 12 years. The average age of the participants was 62 years old at the start of the study.
It indicated that it was favourable to have vitamin D blood values of around 42 to 100nmol/l. Having higher or lower values indicated that patients had greater risk of dying from cardiovascular disease.
Lead study author Professor Jutta Dierkes said: “We discovered that the right amount of vitamin D reduces the risk of death substantially. However, too much or too little increase the risk.”
However, according to Professor Dierkes, it was difficult to give general a recommendation of how much vitamin D supplementation patients should take.
She said: “The optimal amount of vitamin D-supplement varies from one person to another. It depends where you live, and what kind of diet you have.”
‘Normal’ vitamin D intake cuts mortality in cardiovascular patients
For example, she noted that the Nordic countries recommended an intake of 10 microgram per day from all vitamin D-sources, the US recommends 15 micrograms and Germany 20.
“Even if Norwegians receive less sun then the Germans, the Norwegians have more fish in their diet. Fish and cod liver oil are important sources to vitamin D during the winter, in addition to physical activities outdoors during the summer,” she said.
Professor Dierkes advised clinicians to measure vitamin D levels in all patients who have experienced cardiovascular diseases, so they can be better regulated and the need for supplements assessed.
“It is, however, important to take in account that the levels vary seasonally A measurement in September will not show the same results as in January,” she said, highlighting sunlight differences.