"Oily fish such as salmon and mackerel also contain a lot of vitamin D3," an Ergo-Log reader e-mailed. "I don't eat that every day, but I do take my fish oil capsules faithfully. Do I still need a vitamin D supplement?"
Study
Habeeb Alhabeeb, affiliated with King Fahad Medical City in Saudi Arabia, found 10 previously published trials in the scientific literature involving a total of 610 subjects.
The subjects had been given fish oil or a placebo, and researchers had determined the effect of the supplement on their vitamin D level.
Results
In the trials that Alhabeeb managed to obtain, supplementation with fish oil increased the vitamin D level by an average of 3.8 nanograms per milliliter. That's more than nothing, but it won't get someone with a vitamin D deficiency to optimal vitamin D levels.
Someone with a vitamin D deficiency has less than 20 nanograms of vitamin D in one milliliter of blood. An optimal vitamin D level is above 50 nanograms per milliliter of blood.
Alhabeeb was able to calculate that the duration of the supplementation was a factor. In trials lasting longer than 8 weeks, the level rose by slightly more than 9 points. In shorter trials, level dropped a few tenths of a point.
Source:
Crit Rev Food Sci Nutr. 2022;62(11):3116-23.
Study
Habeeb Alhabeeb, affiliated with King Fahad Medical City in Saudi Arabia, found 10 previously published trials in the scientific literature involving a total of 610 subjects.
The subjects had been given fish oil or a placebo, and researchers had determined the effect of the supplement on their vitamin D level.
Results
In the trials that Alhabeeb managed to obtain, supplementation with fish oil increased the vitamin D level by an average of 3.8 nanograms per milliliter. That's more than nothing, but it won't get someone with a vitamin D deficiency to optimal vitamin D levels.
Someone with a vitamin D deficiency has less than 20 nanograms of vitamin D in one milliliter of blood. An optimal vitamin D level is above 50 nanograms per milliliter of blood.
Alhabeeb was able to calculate that the duration of the supplementation was a factor. In trials lasting longer than 8 weeks, the level rose by slightly more than 9 points. In shorter trials, level dropped a few tenths of a point.
Source:
Crit Rev Food Sci Nutr. 2022;62(11):3116-23.
