How much calcium do I need per day, and can too much be harmful?
Calcium requirements range from 800 mg (young children) to 1500 mg per day (older adults, teenagers, postmenopausal women). Up to 2000 mg per day is safe for most people; aim to get calcium from food wherever possible.
Calcium requirements vary by life stage. Children aged 6 to 10 need 800 to 1200 mg per day. Teenagers and young adults up to age 24 need 1200 to 1500 mg: this is when bone mass reaches its peak. Adult women up to age 50 and men up to age 65 get by with 1000 mg. Postmenopausal women not on hormone therapy and everyone over 65 have the highest requirement: 1500 mg per day. During pregnancy and breastfeeding the recommended amount is 1200 to 1500 mg per day; discuss this with your doctor.
Aim to get calcium from food first: dairy products and fortified plant-based drinks are good sources. On a label, look at the amount of elemental calcium per tablet, for example 500 or 1000 mg. Whether you drink powdered milk or regular milk makes no difference to absorption. A supplement is worthwhile if you can demonstrate that your dietary intake is insufficient.
For bone preservation in people over 50, participants in studies received 1000 to 1200 mg of calcium per day, combined with 800 IU of vitamin D, for at least 12 to 24 months. In people living in care facilities, this reduced the risk of fractures by around 30%. Vitamin D is essential here: without sufficient vitamin D, the intestine absorbs calcium less effectively. Calcium supplements do increase the risk of kidney stones, and several analyses point to a possible increased risk of heart attack, so take them only when there is a clear reason to do so. Discuss this with your doctor.
Up to 2000 mg per day is safe for most people; above that level the risk of side effects increases. Calcium can temporarily inhibit iron absorption, but in most people this has no long-term effect on iron status. If you have an iron deficiency, try not to take calcium and iron at the same time. Also avoid taking calcium at the same time as thyroid medication or a fluoroquinolone antibiotic, as it can reduce the effectiveness of those medicines. Consult your doctor or pharmacist in that case.
All claims are based on NIH consensus guidelines, a meta-analysis on vitamin D and fractures, and separate reviews on calcium and iron, athletes, and pregnancy. Most recommendations rest on observational studies and expert consensus; there are no large randomised trials that substantiate exact intake recommendations through direct comparison.
Do you really need calcium supplements for strong bones?
Whether you need calcium supplements depends strongly on your age and situation: for healthy women before the menopause there is no evidence of benefit, while women over 50 may benefit from calcium plus vitamin D, provided you weigh the increased risk of kidney stones and the uncertain cardiac risk with your doctor.
Do calcium and vitamin D supplements really help against bone loss?
Calcium and vitamin D together can improve bone density and slightly reduce the risk of hip fractures when a deficiency has been confirmed. Vitamin D as a standalone supplement does little if your blood levels are already adequate.
What does magnesium do for your bone strength?
Getting enough magnesium appears to be good for your bones, but whether supplements truly prevent fractures has not yet been convincingly demonstrated. First make sure your intake through diet is in order; consider supplementation only if you know you are deficient, and discuss this with your doctor if in doubt.
What is the optimal vitamin D level?
For bone health, 50 nmol/l is the most widely accepted target level, achievable with 800 IU of vitamin D per day. Whether a higher level also provides benefit beyond the skeleton has not been demonstrated.
Are calcium supplements bad for your heart?
Calcium supplements may be associated with an increased heart risk, but not all studies confirm this. It is best to get calcium from your diet, and discuss with your doctor whether a supplement is truly necessary for you.
Is a calcium score of my heart worth doing?
For people between 40 and 75 years old in a grey zone regarding statins, a calcium score is a well-supported tool for making a well-considered decision about medication together with your doctor.