Subgroup analysis for worldwide region-specific levels of breast-milk DHA (a) and arachidonic acid (AA; b) by accessibility to marine foods: , with accessibility; , without accessibility; NAR, North American region; OCR, Oceania region; EUR, European region; EMR, Eastern Mediterranean region; AFR, African region; SAR, South American region; ASR, Asian region. Values are means with their standard deviation represented by vertical bars (seventy-eight studies from forty-one countries were included with 4163 breast-milk samples of 3746 individuals). a,bMean DHA or AA values with unlike superscript letters were significantly different (P<0·05)