Sacred pastors should take care to ensure that the faithful who participate in the rite or are present at it are as fully aware as possible of the Catholic teaching on the form of Holy Communion as set forth by the Ecumenical Council of Trent. Above all, they should instruct the Christian faithful that the Catholic faith teaches that Christ, whole and entire, and the true Sacrament, is received even under only one species, and consequently that as far as the effects are concerned, those who receive under only one species are not deprived of any of the grace that is necessary for salvation. (No. 282)If, especially after encouragement, the option to receive from the Chalice is not taken up and might seem to be causing a division, there is a clear instruction on what to do. Stop it.
The chalice should not be ministered to lay members of Christ’s faithful ...where a notable part of the people continues to prefer not to approach the chalice for various reasons, so that the sign of unity would in some sense be negated. [Redemptionis Sacramentum 102]
Redemptionis Sacramentum, directing us to the Second Vatican Council and the Council of Trent, gives a clear understanding of the principles involved:
Whilst there may be reasons for encouraging communion under both species, there may also be good, practical and theological reasons for not doing so. After all, the Council of Trent “induced by weighty and just reasons,- has approved of this custom of communicating under one species”. [Ecumenical Council of Trent, Session XXI, 16 July 1562, Decree on Eucharistic Communion, Chapter 2.]
[100.] So that the fullness of the sign may be made more clearly evident to the faithful in the course of the Eucharistic banquet, lay members of Christ’s faithful, too, are admitted to Communion under both kinds, in the cases set forth in the liturgical books, preceded and continually accompanied by proper catechesis regarding the dogmatic principles on this matter laid down by the Ecumenical Council of Trent. [Cf. Ecumenical Council of Trent, Session XXI, 16 July 1562, Decree on Eucharistic Communion, Chapters 1-3: DS 1725-1729; Second Vatican Ecumenical Council, Constitution on the Sacred Liturgy, Sacrosanctum Concilium, n. 55; Missale Romanum, Institutio Generalis, nn. 282-283.