How can you tell if you're lacking calcium? You have two options: 1. Bone Mineral Density (BMD) Testing: If normal, then it seems adequate for the moment. But BMD scans usually cover parts of your skeleton rather than total bone reserves. Blood tests aren't helpful as serum calcium is tightly regulated by the body at bones' expense—low serum calcium rarely indicates a deficiency; usually signifies regulation malfunction. 2. Dietary Benchmarking: According to the Chinese Dietary Guidelines, adult intake should be: 300–500ml milk + 250g leafy greens + 50g tofu + 50g fish/meat + 1 egg. How to take calcium? Get it from food, Preferably. Supplement only if necessary Dietary Options Dairy products (milk, yogurt), leafy greens (bok choy and kale), calcium-fortified tofu, and sardines with bones are all high in calcium. When You Need Supplements If you are a picky eater, have dietary limitations or belong to vulnerable groups (teens, elders) —then supplements become necessary. Supplement Types - Inorganic Calcium: Calcium carbonate (needs stomach acid for absorption, suitable if having healthy digestion). - Organic Calcium: Calcium citrate (suitable for seniors or people with low stomach acid). Dosing Adults missing one dietary source (e.g. milk) should take 300mg/day. - 500mg/day in Seniors/Children. Safety Tips Taking more than 500mg/day—can lead to vascular calcification and cardiovascular risks. Nonetheless, The American Heart Association states supplements by elemental calcium (not compound weight) pose no risks within recommended dosage. Vitamin D Partnership Calcium needs vitamin D for absorption (600–800 IU/day). Sunlight helps production —15–30 mins midday weekly exposure sufficient. Don't Take Multimineral Supplements Those eating healthy don't need them. Most have very little calcium, but too many minerals. Special Instances 1. Diabetes/Heavy drinkers: Magnesium intake of (400–420mg/day for men; 310–320mg women). Alcohol reduces absorption, while diabetes increases excretion. 2. Vegetarians/men planning pregnancy: zinc Supplementation (11mg/day). Deficiency affects Sperm Development 3. Health Conditions: Seek medical advice for a tailored plan on anemia, pregnancy/lactation and chronic diarrhea.