For everyday dietary calcium deficiency - the silent, common kind - the home toolkit is genuinely strong. Food is the treatment.

The daily plate upgrades

Milk and curd: 300-500 ml milk equivalent a day covers a large share of adult needs; curd, buttermilk and paneer all count
Ragi (finger millet): the standout Indian grain for calcium - several times more than wheat or rice; ragi porridge, dosa, roti
Sesame (til): a tablespoon of sesame seeds or til chutney/laddu adds a meaningful dose
Green leafy vegetables: amaranth (chaulai), methi, drumstick leaves, bathua - regular rotation
Pulses and soy: soybean and tofu are among the richer plant sources
Nuts: almonds in small daily amounts
Small fish eaten with bones (where customary): a traditional whole-calcium source

The absorbers and the blockers

Vitamin D decides absorption: 15-20 minutes of midday sunlight on arms/legs a few times a week; fortified foods; supplements if a test shows deficiency
Spread calcium through the day: the gut absorbs a few hundred milligrams per meal, not a whole day's worth at once