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RECENT work on the differentiation of vitamins A and D has emphasised the need of a vitamin D-free source of vitamin A. This has been chiefly sought for in fresh spinach leaves, which have been shown by many investigators to contain considerable amounts of vitamin A. However, in spite of much work on the problem, the possible presence of vitamin D in spinach leaves still appears to be a matter of debate.
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Willimott et al. (1927) studied this question.
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