1 The most common sign of hypocalcemia is what is called "neuromuscular irritability." Your nerves and muscles, which are directly related to blood calcium levels, may spasm or twitch.
2 If your blood test results indicate hypocalcemia, you may notice muscle cramps in your legs or your arms.
3 The symptoms of hypocalcemia you experience may relate to how fast or how slowly the fall in blood calcium levels occur.
4 If you have long-standing low blood calcium levels, you may notice no symptoms of hypocalcemia.
5 If you have an "acute" or sudden drop in your blood calcium level, you may notice more twitching.
6 You may notice, with mildly lowered blood calcium levels, numbness and tingling of your fingers and toes.
7 You may notice that you are depressed, or more irritable if you have mildly low hypocalcemia.
8 With severely lowered blood calcium levels, you may become confused or disoriented. Your heart muscle may contract irregularly due to the electrolyte disturbance.
These are some low calcium symptoms I found on a website.
The UK RDA is 800mg To get that you'd have to consume nearly 400g of collard greens (the most, or one of the most calcium dense green leafy) vegetable. Or even more than that of Kale etc. Calcium from spinach is not absorbed as well. Tofu like you say is good if its made with calcium salts. If you have some calcium enriched soy milk (on your cereal) or coffee, that helps, too. 100g of sunflower seeds for isntance has 116 calcium, unless it is unhulled sesame seeds which has a lot (although they are hard to find and the calcium in the hulls is harder to absorb).
Just to give an example, you could eat
100g collard greens 210mg,
130g kale 93.6mg
100g sunflower seeds- 116mg
150g broccoli - 74mg
100g kidney beans - 143mg.
After all of those calcium rich foods its still only around 550mg calcium, while the UK RDA is 800, and the USA is 1000.
Sorry to go on and on

!
Just maybe check it out because it could be one of the reasons.
Although the effeminate nature of my username may suggest otherwise, my gender actually falls into the male category.