LaTeX/MathJax support for Help/Rd files?

Another example from a .Rd file: \deqn{h_{n} = 1 - \frac{(e_{ls} - e_{a})}{e_{ls}}}
This renders beautifully with MathJax, but in the help file looks like: h_{n} = 1 - \frac{(e_{ls} - e_{a})}{e_{ls}}

Similarly, if I add already formatted bibliographic information:
Horita J, K Rozanski, S Cohen. 2008. Isotope effects in the evaporation of
water: A status report of the Craig-Gordon model. Isotopes in environmental
and health studies 44 (1): 23–49. DOI: 10.1080/10256010801887174.

I get:
Horita J, K Rozanski, S Cohen. 2008. Isotope effects in the evaporation of water: A status report of the Craig-Gordon model. Isotopes in environmental and health studies 44 (1): 23–49. DOI: 10.1080/10256010801887174.

This is less of a big deal, but still odd that "-" is interpreted as "–".

Thanks for your responses!