It referred to Vitamin D and its importance in dealing with fertility issues. Austrian scientists have shown that vitamin d deficiency is associated with both male and female fertility issues. Another study in the Journal of Nutrition showed the Vit D deficient rats decreased their fertility by 75%.
How do you know if you are deficient in Vit D?
A simple blood test can look at your Vit D levels. The doctor will likely order Vitamin OH 25 D3 and the optimal levels should be between 75-100.
Optimizing Vitamin D can be done with liquid Vit D3 drops or tablets though some experts are recommended trying to get at least 10 minutes of sun exposure per day. If you opt for the most natural way to increase your Vitamin D that is through sun exposure, you must expose as much of your body area as possible (without getting arrested) and no sunscreen.
The amount recommended if you are deficient in Vitamin D varies but 4000IU is usually a good place to start. Retest your Vitamin D levels in 6 weeks from starting supplementation to make sure there is some improvement.
If through either of these methods your vitamin D levels do not increase then also check thyroid and adrenal hormone levels; TSH, FT4, FT3, thyroid antibodies, am cortisol and dhea.
These tests may give you a clue as to what may be effecting your vitamin D levels and also your fertility.