Table 4.
Recommendations by researchers and reviewers for adult vegans/total vegetarians (VGNs) (most recent studies first).
| Author, Year | Recommendation: Males; Females Combined |
18:2n-6 LA | 18:3 n-3 ALA | 20:5 n-3 EPA | 22:6 n-3 DHA | n-6:n-3 or Omega-3 Index |
|---|---|---|---|---|---|---|
| Agnoli et al., 2017 [55] | Females | Limit intake of sources of n-6 FA, & TFA. Limit consumption of processed, deep-fried foods, and alcohol. | - | Pregnant/breastfeeding or women with increased requirement for long chain n-3 fatty acids, should be advised to consume an algae-based supplement of known nutrient content. | Pregnant/breastfeeding or women with increased requirement for long chain n-3 fatty acids, should be advised to consume an algae-based supplement of known nutrient content. | - |
| Combined-Males and Females | - | Improve n-3 nutritional status by regular consumption of good sources of alpha-linolenic acid. | - | - | - | |
| Burdge et al., 2017 [34] | Females | - | - | - | Need more cognitive studies for children of vegetarian females due to low DHA levels. | - |
| Pinto et al., 2017 [9] | Combined | - | Further research whether populations with low n-3 status are more at risk of having a pro-inflammatory profile. | - | - | - |
| Melina et al., 2016 [5] | Females | - | - | - | Low dose microalgae DHA supplements for pregnancy and lactation. | - |
| Combined | High intakes of LA may suppress ALA conversion. | May be prudent to ensure higher intakes of ALA. N-3 needs of healthy individuals can be met with ALA alone; endogenous synthesis of EPA and DHA from ALA is sufficient. | Clinical relevance of reduced EPA and DHA status in VGNs are unknown. Low-dose micro-algae based DHA supplements are available for those with increased needs. | Clinical relevance of reduced EPA and DHA status in VGNs are unknown. Low-dose micro-algae based DHA supplements are available for those with increased needs. | A ratio of LA/ALA not exceeding 4:1 has been suggested for optimal conversion. | |
| Harris, 2014 [56] | Combined | Consume more ALA and less LA to increase the Omega-3 Index. | Consume more ALA and less LA to increase the Omega-3 Index. | - | - | Omega-3 Index >8%. |
| Sarter et al., 2014 [16] | Combined | - | - | VGNs respond robustly to a relatively low dose of a vegetarian omega-3 supplement. |
VGNs respond robustly to a relatively low dose of a vegetarian omega-3 supplement. |
No direct evidence that omega-3 index confers additional health benefits over and above their already protective VGN diet. |
| Saunders et al., 2013 [15] | Combined | - | Double current AI of ALA if no direct sources of EPA and DHA are consumed. Increased needs or reduced conversion may benefit from DHA and EPA supplements derived from microalgae of 200–300 mg/day of DHA and EPA (pregnant and lactating women) and reduced conversion ability. | - | - | - |
| Craig, 2010; Review [51] | Combined | - | Regular consumption of plant foods naturally rich in n-3 fatty acid ALA, such as ground flaxseed, walnuts, soy products, and hemp seed beverages. | - | Pregnant and lactating women may benefit from DHA-fortified foods and microalgae-derived DHA supplements. | - |
| Welch et al., 2010 [44] | Combined | - | Further research for conversion of ALA to long chain n-3 PUFAs for maintenance of adequate status in non-fish and fish-oil consumers is required. | - | - | - |
| Simopoulos, 2008 [57] | Combined | - | - | - | - | Ratio of 4:1 is associated with 70% decrease in total mortality in secondary prevention of cardiovascular disease. |
| Kornsteiner et al., 2008 [40] | Combined | - | Erythrocyte phospholipid n-3 status of VGNs is critical. It is important to maintain n-3 fatty acid intake during adult life. | - | - | Ensure physical, mental and neurological health, reduce n-6/n-3 ratio with an additional intake of direct sources of EPA and DHA, regardless of age and gender. |
| Mann et al., 2006 and Li et al., 1999 (Mann used data collected from Li, 1999) [45] | Combined | - | Advised to increase intake of n-3 fatty acids to increase platelet PL n-3 PUFA and reduce platelet aggregability. | - | - | - |
| Rosell et al., 2005 [10] | Combined | - | Suggests (with caution) VGNs increase intake of ALA and limit intake of LA to optimize FA status. The importance of long chain fatty acids in the diet needs further investigation. | - | - | - |
| Davis et al., 2003 [53] | Combined | 5.5–8% Kcals from n-6 FA. Reduce high n-6 oils in the diet, decrease processed foods. Primary fat should be MUFA. | <1.5–2% of calories should be obtained from n-3. Decrease EtOH and trans fatty acids to increase conversion of ALA to EPA and DHA. Double intake of ALA; provide >1% of energy from n-3 or about 1.1 g/1000 calories. Increased needs require 2.2 g/1000 calories. Aim for 2–4 g of ALA/day. | Not essential, but it is important to ensure sufficient levels by relying on conversion from parent fatty acids. Two important steps to improve EPA status: 1) Maximize conversion of ALA to EPA and DHA and 2) Provide a direct source of EPA and DHA. | Not technically essential, but ensure sufficient levels by relying on conversion from parent fatty acids. Supplements of DHA should be 100–300 mg/day. DHA and ALA should also be adequate. | To achieve the 4:1 ratio, <1.5–2% of calories should be obtained from n-3 and 5.5–8% of calories from n-6 FA. |
| Simopoulos, 2000 [54] | Combined | - | - | - | - | Ratio was 1:1 to 2:1 in ancient diets. Present ratio is 10 to 1:20 to 25 to 1- indicates a deficiency in Western Diets of n-3. |
| Fokkema et al., 2000 [43] | Combined | - | - | - | - | Found a 3:1 ratio increased EPA from 0.3 to about 1.0% in VGN plasma. A 3.7 g/day ALA diet for 4 weeks (ratio of 3.8:1) augmented ALA about 1% more. Total n-3 levels increased from 2.3 to 3.4% in plasma. DHA status was not increased. |
| Agren et al., 1995 [42] | Combined | Depressed levels of n-3 FA are depressed due to very low diet levels and high LA and oleic acid intake. | - | - | - | - |
| Sanders et al., 1978 [46] | Females | - | More research is needed on low delta 4 desaturase in lactating women. | - | - | - |
| Combined | - | Further research needed to establish whether differences in the proportion of n-3 derivatives in tissues are of physiological importance. | - | - | - |