Why milk and other dairy products may be a safer option than calcium supplements

Dietitians and members of the medical profession have, for many years, been recommending the use of calcium supplements for individuals who have an inadequate dietary calcium intake (e.g. strict vegetarians or vegans, and patients with lactose intolerance or milk allergy) and postmenopausal women and older men to prevent osteoporosis, a debilitating and sometimes fatal condition.

Calcium supplement risks

Recent research is now questioning the safety of recommending the use of calcium supplements. A study conducted with 1471 postmenopausal women who either received calcium supplements (1 g of elemental calcium a day) or placebo (dummy medication) for a period of five years, found that:

• Myocardial infarcation or heart attacks, strokes and sudden death were more common in the group of women who took calcium supplements for 5 years.
• Calcium supplementation in healthy post-menopausal women is associated with upward trends in cardiovascular event rates.

Although, some scientists refute these results, there is concern that recommending calcium supplements may be associated with unacceptable results, particularly in older people.

The role of vitamin K in healthy bones and arteries

Intake of calcium from dairy together with vitamin K2 and vitamin D will build strong bones at any age without endangering your health

The Rotterdam Study, another very large study conducted in Europe, indicated that vitamin K2, one of a group of fat-soluble vitamins called quinines that are vital to ensure that the body makes proper use of calcium for healthy bones, arteries and tissues, is not only essential for blood coagulation and osteoporosis prevention, but also to protect against cardiovascular disease. Vitamin K2 activates a special bone protein called osteocalcin, which binds calcium effectively in the bones, thus preventing this calcium from moving onto the blood stream and being deposited in the arteries that may have fatal consequences. 

Guidelines for supplementation

Healthy bones are the foundation for a vital, energetic life!

If supplementation of calcium cannot be avoided, supplements containing calcium citrate, calcium carbonate, calcium lactate, calcium gluconate or tricalcium phosphate can be used. These calcium supplements are comparably well absorbed if they disintegrate. Tablets should therefore be chewed, or an effervescent product should be used. Calcium supplements that contain calcium citrate-maleate, which is particularly well-absorbed, are preferred. It is further recommended that supplements should contain a combination of calcium, vitamin D and vitamin K2. Packaging should indicate 1000mg elemental calcium as the amount of calcium available for absorption.

Who needs high calcium intakes

High calcium intakes varying between 300 mg (infants) and 1300 mg (girls up to the age of 18 years) on a daily basis are required by the following vulnerable populations:

• Growing infants and children
• Teenagers, particularly young women and pregnant teenagers
• Pregnant and breast-feeding women
• Postmenopausal women
• Older people with reduced stomach acid concentrations, which hamper calcium uptake
• Strict vegetarians and vegans

The most critical life stages for bone health are childhood and young adulthood. It has been estimated that 90% of an individual’s bone mineral content is deposited by the age of 19 and 99% is deposited by the age of 22 years.

Women are more susceptible to osteoporosis and require higher calcium intakes not only after menopause, but during the vital years between 8 and 18 when they are laying down their bone calcium stores for the rest of their lives. Ironically, this group tend to have their lowest calcium intake (often as a result of erroneous avoidance of milk and dairy products for slimming purposes) and the highest incidence of calcium deficiency.

Negative eating habits

The following eating habits have a negative effect on nutrient intake for building strong bones:

• Very low kilojoule diets
• Cutting out calcium-rich foods such as milk and dairy products, as well as fruits, vegetables and whole grains
• Eating or drinking high-energy, highly processed foods at the expense of more nutritious foods (e.g. drinking sweetened cold drinks instead of milk)
• Skipping meals, especially breakfast

Factors that promote bone health

Bone health is determined by:

• Adequate dietary calcium intake
• Adequate vitamin D intake or production
• Healthy eating habits that include milk and dairy foods in the diet (see list of required nutrients below)
• Regular physical activity (preferably weight-bearing exercises)

Nutrients that develop strong bones

The following nutrients play a vital role in developing strong bones:

• Calcium (NRV: 1300 mg/day)
• Phosphorus (NRV: 1250 mg/day)
• Magnesium (NRV: 420 mg/day)
• Fluoride (DRI: 4 mg/day)
• Vitamin D (RDA: 5 microgram (μg)/day)
• Vitamin K (DRI: 120 microgram (μg)/day)

RDA = Recommended Dietary Allowance is for individuals older than 13 years

DRI = Dietary Reference Intake (Adults), is used where RDA’s is not available

NRV = Nutrient Reference Value is for individuals 4 years and older

References 

Miller et al. 2001. The importance of meeting calcium needs with foods. Journal of the American College of Nutrition, 20(2):168-185S.
Weaver CM. 2006. Back to basics: Have milk with meals. JADA, 106(11):1756-8.
Gueguén L & Pointillart DVM. 2000. The bioavailability of dietary calcium. Journal of the American College of Nutrition, 19(2):119S-136S.
Straub DA. 2007. Calcium supplementation in clinical practise: a review of forms, doses, and indications. Nutr Clin Pract, 22:286-296.
Anderson DM. 2008. Nutrition in bone health. In Mahan LK & Escott-Stump S. Krause’s food and nutrition therapy, 12th ed. WB Saunders: London.
Gallagher ML. 2008. The nutrients and their metabolism. In Mahan LK & Escott-Stump S. Krause’s food and nutrition therapy, 12th ed. WB Saunders: London.
Boland MJ et al. 2010. Effects of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ, 34:c3691.
Rahemtulla Z et al. 2005. The palatability of milk-based and non-milk-based nutritional supplements in gastrointestinal cancer and the effect of chemotherapy. Clinical Nutrition, 24:1029-1037.
Darmon P et al. 2008. Oral nutritional supplements and taste preferences: 545 days of clinical testing in malnourished in-patients. Clinical nutrition, 27:660-665.