Vitamin D and omega-3 fatty acids are essential nutrients involved in numerous metabolic processes that play a significant role in many chronic health conditions. During the past several years, numerous studies have shown that omega-3 fatty acid supplementation can affect serum vitamin D levels, but the results have been inconsistent. These inconsistencies may have been due to the dose, duration, or statistical power of the studies.

According to a review published 2 weeks ago in Critical Reviews in Food Science and Nutrition, researchers investigated the effect of omega-3 fatty acid supplementation on vitamin D levels. This meta-analysis consisted of 10 randomized controlled trials with a total of 601 participants who reported circulating vitamin D levels before and after supplementation with omega-3 fatty acids. As a result, there was a significant increase in vitamin D levels after omega-3 fatty acid intake. Vitamin D levels were significantly increased by approximately 9 ng/mL when supplementation continued for more than 8 weeks and when the baseline vitamin D level was less than 20 ng/mL. In addition, dosing at 1 gram per day resulted in higher vitamin D levels when compared to other dosages, but all doses led to an increase in vitamin D levels.

The relationship between vitamin D and omega-3 fatty acids is unclear. Deficiencies or insufficiencies of these two nutrients are important health concerns in clinical practice. This review specifically looked at the effects of omega-3 fatty acids on vitamin D levels; however, it is still optimal to assess both nutrients to address this accordingly. The recent review, as described, demonstrates the significance of the interrelationships between different nutrients and the importance of a comprehensive approach as opposed to monotherapies.

 Previous research has shown the intricate interrelationships among the fat-soluble vitamins, magnesium and vitamin D levels, and omega-3 fatty acid status and B vitamins. A study published in 2018 in the American Journal of Clinical Nutrition demonstrated that magnesium can also increase vitamin D levels similar to omega-3 supplementation. Another study published in the Journal of Alzheimer’s Disease demonstrated that B vitamins had no effect on cognitive decline when omega-3 levels were low, but when omega-3 levels were in a normal upper range, B vitamins slowed cognitive decline and brain atrophy.

By Michael Jurgelewicz, DC, DACBN, DCBCN

Source: Alhabeeb H, Kord-Varkaneh H, Tan SC, et al. The influence of omega-3 supplementation on vitamin D levels in humans: a systematic review and dose-response meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2020;Dec 25 [online ahead of print]:1-8. doi:10.1080/10408398.2020.1863905.