Vegans have lower levels of vitamin D, omega-3 fatty acids EPA and DHA, ferritin and cholesterol than non-vegetarians - study

  • In a study published today it was found that vegans have lower total and LDLD cholesterol but also lower omega-3 fatty acids (EPA and DHA), beta carotene, iodine, vitamin B12 and folic acid levels in their bloodstream; higher isoflavones (daidzein and genistein), caffeic acid and ferrulic acid. Vegans also consumed less fruits and berries than non-vegetarians. There are a few points to be made about the results of this study:
  • Vegans were severely deficient in vitamin D3, having 1/3 of the levels of non-vegetarians: 31 nmol/L falls into the severe deficiency category, which increases the risk of cancer, immune conditions and heart disease. Since adequate amounts cannot be taken by vegetarian food and are only in plentiful supply by sun exposure or by animal foods, this result simply shows that vegans (especially women) do not just avoid meat but also they neurotically avoid the sun, even the 30' per day needed to maintain healthy levels of vitamin D3. In contrast, non-vegetarians have a half-decent level of 90 nmol/L. In order to to assist with immune function and cardiovascular / cancer disease protection, 4000IU per day of vitamin D3 supplementation is recommended to vegans avoiding the sun. Actually, vegans were found to receive 50% more vitamin D supplementation than non vegetarians, but unfortunately that was at very low levels and of the wrong/inactive type (vitamin D2).
  • Vegans have 7-12x times more isoflavones than other people, due to their excessive consumption of soy products. This can help with menopausal symptoms, but in any other respect it is considered excessive.
  • Vegans have 1.5-2x times more polyphenols (caffeic acid, ferulic acid) but 2.5x times less carotenoids, such as beta carotene. This presents a mixed picture.
  • Vegans had 1/3 of the ferritin levels of non-vegetarians, indicating iron deficiency problems
  • Vegans have 60% of folic acid and vitamin B12 than non-vegetarians, despite receiving 5x times more (!) supplementation of vitamin B12 than non-vegetarians
  • Vegans had 1/4 of the EPA highly unsaturated fatty acid (HUFA) omega-3 and 1/3 of the DHA highly unsaturated fatty acid levels of non-vegetarians, who clearly either ate a lot of oily fish or took fish oil supplements. Vegans instead tried to boost their EPA and DHA HUFA omega-3 levels by taking more flaxseed/linseed oil and hoping to convert LAN found in this'll into EPA and DHA. However, as the results of the study show, this evidently and predictably did not work (the body only converts 5% of LNA into EPA or DHA). The advice for vegans is to use the now widely available vegetable source EPA and DHA, instead of expecting their body to convert 5% of LNA into EPA and DHA.
  • Vegans had the same omega-9 (oleic acid) levels as non-vegetarians, indicating the same intake of olive oil
  • Vegans eat only 1/4 of berries than non-vegetarians, the same amounts of fruits in general, 2.5x times more fruit juices, 9x times more berry juices, 3x times more margarine (probably the worst fat you can eat), 40% less coffee, , 50% more tea, twice more sugar (!), 30% less sweets, 40% more chocolate, 30x times more tofu, only 10% more vegetables and 5x times more pulses.
  • Vegans predictably had 60% of the protein intake than non-vegetarians, but it was still at adequate levels (non-vegetarians probably took too much protein); 20% less overall fat; 20% more polyunsaturated fatty acids; 50% of saturated fat; but also 50% more carbs; 30% more fibre; 30% less vitamin C (!); same amounts of calcium; 25% more iron (but they still had less ferritin, showing poor iron absorption); and the same amount of calories per day.
  • Source: Food and Nutrient Intake and Nutritional Status of Finnish Vegans and Non-Vegetarians
  • Abstract: DISCUSSION: 4.1. Plasma lipids, antioxidants, and isoflavones. Some health-related and nutritional measures were more favorable in vegans than in non-vegetarians. Most importantly, the serum total cholesterol was 20% and LDL cholesterol was 25% lower in the vegan group than in the non-vegetarian group. Furthermore, vegans showed a more favorable fatty acid profile and higher serum concentrations of certain polyphenols compared with the non-vegetarians. These findings were likely the result of high consumption of rapeseed oil and margarines as well as soy and rye products. The vegans consumed relatively small amounts of fruit, berries, nuts, and root vegetables, which was the likely cause of the lower serum concentrations of β-carotene (p = 0.001) and α-tocopherol (p = 0.003) compared to the non-vegetarians. However, after calculating the ratio of serum β-carotene and α-tocopherol to cholesterol concentration, and when adjusted to the new threshold of statistical significance obtained in Bonferroni calculation for multiple comparisons (p<0.0016) the differences in these antioxidant nutrients were not statistically significant. The poorer antioxidant vitamin status of vegans disagrees with the findings of earlier studies [35]. This is likely because the non-vegetarian subjects of this study were health conscious, as shown by their high consumption of different vitamin and mineral supplements as well as fruits and berries. 4.2. Vitamins B12 and D. Despite the use of nutritional supplements, the serum vitamin B12 concentrations in the vegans were lower compared to the non-vegetarians (p = 0.002); however, only 5% of vegans had serum vitamin B12 concentration below 140 pmol/L. It therefore appears that the consumption of vitamin B12 supplements, which 91% of the vegan subjects consumed, maintained their serum vitamin B12 concentrations within the reference limits. The onset of deficiency symptoms such as neuropsychiatric disorders and megaloblastic anemia usually occurs in 5–10 years when the serum vitamin B12 concentration is below 150 pmol/L [36]. The serum total concentration of vitamin D (25-hydroxyvitamin D2 and D3) was 34% lower in the vegans than in the non-vegetarians. However, the vegans had higher concentrations of 25-hydroxyvitamin D2 (p<0.001). The fraction of subjects having serum vitamin D concentration >75 nmol/L, which is the level proposed by some researchers to be optimal for preventing adverse health conditions [37], was 10% in vegans and 78% in non-vegetarians. In addition, more vegans had a serum vitamin D concentration ≤50 nmol/L as compared to the non-vegetarians (24% vs. 6%). The reasons for the marginal vitamin D status are presumably neglecting supplementation (23% of vegans), irregular supplementation, and, possibly, the time of sampling. 25-hydroxyvitamin D3 (calcidiol) concentrations are typically lowest during the winter [38]. Similar lower calcidiol concentrations were reported in Finnish, British, and Vietnamese vegans. [8, 9, 20, 21]. 4.3. Iodine and selenium. All vegan subjects and 91% of the non-vegetarian subjects had iodine concentrations lower than the WHO’s limit for mild iodine deficiency (<100 μg/L urine). These data indicate that iodine intake may be insufficient in the Finnish population but particularly so in vegans, who do not consume milk products, the main source of iodine in many countries. Previously, goiter caused by iodine deficiency was common in Finland. However, after the fortification of table salt and cattle feed with iodine started some fifty years ago, iodine-deficiency-related goiter was eradicated. Today, the consumption of iodized table salt has decreased, partly because the food industry does not use iodized salt. Therefore, recommendations regarding iodine intake are not met by the general population [12]. Previous studies in vegans have also reported low urinary excretion of iodine. [6, 22, 23]. The serum selenium concentrations were lower in vegans than in non-vegans, however, on the whole, the values were similar to those found in countries that do not add selenium to fertilizers. It should be noted that Finland is the only country in the world that uses this strategy for supplementing the population with selenium [39]. The selenium intake was above the current nutrition recommendations [10] in both groups. The difference between groups is likely because dietary selenium is mainly obtained from animal products, which make up over 70% of the selenium intake in Finland [39]. 4.4. n-3 fatty acids. Compared to the non-vegetarians, the proportions of C15:0, C17:0, and CLA, obtained mainly from milk products, were negligible in the vegans, indicating strict compliance with the vegan diet. The percentages of EPA and DHA of all fatty acids were respectively 0.6% and 0.9% in the vegans, and they were clearly lower than in the non-vegetarians. These differences were expected because vegans do not consume fish or fish oil products. However, the observed proportion of EPA in the vegans was still higher than expected. These results support the view that linolenic acid (LNA) is converted to EPA in humans. One may regard the vegans in this study as a high LNA population, as they consumed relatively high amounts of rapeseed oil, a common vegetable oil in the Nordic countries and a rich source of LNA. In countries consuming other types of vegetable oils, vegans would likely show even lower proportions of EPA and DHA in plasma. On the other hand, it should be noted that this issue is not straightforward, because linoleic acid (LA) and LNA compete for enzymes involved in fatty acid metabolism. A previous study among Kenyan Maasai [40] showed that despite a negligible intake of EPA and DHA, the proportion of DHA in red blood cells (RBCs) was no less than half that of a German sub-cohort. The authors speculated that a low intake of LA could also be advantageous and favor the endogenous conversion of LNA to DHA at a state of competition between n-3 and n-6 fatty acids. The serum concentrations of the isoflavones genistein (p<0.001) and daidzein (p<0.001) were considerably higher in the vegans than in the non-vegetarians.