How can I add a border to the top and bottom of an iOS grid in Xamarin?

I have this XAML. What I would like to do is to put a 1px line at the top and bottom of the grid with an iOS renderer. Can someone tell me is there a special way to put a border line just at the top and bottom of a grid using a renderer?

<Grid x:Name="phraseGrid" BackgroundColor="Transparent" 
        Margin="0,55,0,0" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
        <Grid.RowDefinitions>
            <RowDefinition Height="10*" />
            <RowDefinition Height="6*" />
            <RowDefinition Height="80*" />
            <RowDefinition Height="13*" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

        <Grid x:Name="prGrid" Grid.Row="0" Grid.Column="0" 
            Padding="5,0,0,0" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
            BackgroundColor="#EEEEEE">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="25*" />
                <ColumnDefinition Width="25*" />
                <ColumnDefinition Width="50*" />
            </Grid.ColumnDefinitions>
            <Label x:Name="cards" Style="{StaticResource smallLabel}" Grid.Row="0" Grid.Column="0" />
            <Label x:Name="points" Style="{StaticResource smallLabel}" Grid.Row="0" Grid.Column="1" />
            <Label x:Name="timer" Style="{StaticResource smallLabel}" Grid.Row="0" Grid.Column="2" />
        </Grid>