Fatty acid profile, vitamin D, and iodine status in Taiwanese vegans, vegetarians, and omnivores.

OBJECTIVES

Vegan diet - the exclusion of all animal products, even eggs and dairy - ranked the most climate-friendly diet, but concerns persist regarding its nutritional adequacy, particularly for omega-3 fatty acids, vitamin D, and iodine. This study compares the nutritional status of fatty acids, vitamin D, and iodine, among Taiwanese vegans, vegetarians, and omnivores.

MATERIALS AND

METHODS

This cross-sectional study included 45 omnivores, 46 lacto-ovo vegetarians, and 24 vegans. Blood and urine samples were collected to analyze nutritional biomarkers, including erythrocyte fatty acid profiles, plasma vitamin D, and urinary iodine.

RESULTS

Vegans had the lowest median percentage of saturated fatty acids, trans-fatty acids, and omega-3 fatty acids, including EPA and DHA, but the highest levels of omega-6 fatty acids. The medians (P25-P75) of omega-3 index values were 2.6 (2.4-2.8), 3.7 (3.2-4.5), and 5.8 (5.0-6.5) for vegans, vegetarians, and omnivores, respectively. Vitamin D deficiency was most prevalent among vegans (75%), followed by omnivores (36%) and vegetarians (24%). Iodine insufficiency was also more common in vegans (76%) than in vegetarians (57%) and omnivores (56%).

CONCLUSION

Taiwanese vegan diets may be advantageous in lowering saturated fatty acids and trans-fatty acid status but may be associated with a higher risk of deficiency for omega-3 fatty acids, vitamin D, and iodine. Strategies to enhance the adequacy of these nutrients may be needed to improve the quality of vegan diets.