This is one mineral you’ll want to get more of if you suffer from PMS. In 1998, a well-designed study of 466 women found that those who took 1200 milligrams of supplemental calcium daily for three months had a significant reduction in PMS symptoms, especially mood swings, low back pain, food cravings and fluid retention.10 The majority of women experienced a 50 percent reduction in overall symptoms, compared to a 36 percent improvement among women who took the placebo pill. What’s more, the strongest improvement was observed during the third menstrual cycle, which implies that the effect of calcium supplements increases with continued use.
We have a few clues as to how calcium may work to alleviate PMS. Many of the symptoms of a calcium deficiency are similar to those of PMS. And there is evidence that blood levels of calcium are low in women with PMS. Low calcium levels cause an overproduction of parathyroid hormone, which interacts with serotonin in the brain to affect mood, so calcium supplements may ease PMS symptoms by replenishing a deficiency. Interestingly, there seems to be a connection between PMS and development of osteoporosis later in life. Perhaps PMS is a monthly reminder that you’re lacking adequate amounts of calcium in your diet.
If you’re a woman between the ages of 19 and 50, you need 1000 milligrams of calcium each day. For a list of calcium-rich foods, see the Calcium in Foods table on page 17 in chapter 1.
Calcium for Premenstrual Syndrome Photo Gallery
In addition to increasing your intake of calcium-rich foods, consider taking a daily calcium supplement to get up to the 1200 milligram target that was found to be effective in the PMS study. To help you determine your need for a calcium supplement, use my 300 Milligram Rule: one milk serving gives you 300 milligrams of calcium, so for every serving you’re missing and not replacing with other calcium-rich foods, you need to get 300 milligrams of elemental calcium through a supplement. But before you rush off to the health food store, there are a few things to look for when buying a supplement.
Many of my clients have described their frustration at buying a calcium supplement. Should you choose calcium carbonate or calcium citrate? Is a 600-milligram pill better than two 300-milligram tablets? What about added vitamin D and magnesium? To help make your next calcium shopping experience stress-free, follow these guidelines for choosing a high-quality supplement.
1. Look at the source of calcium. There are many types of calcium supplements on the shelf. Here are some of the more common types:
• Calcium carbonate is only about 10 to 30 percent absorbed by the body. The amount you absorb depends on how much stomach acid is present; as people age their stomachs produce less hydrochloric acid. Always take calcium carbonate supplements with meals to increase their absorption. Do not take calcium carbonate at bedtime, unless you take it with a snack. On the plus side, calcium carbonate is the most inexpensive type of calcium, and you can get 500 milligrams of elemental calcium in one pill.
• Calcium citrate is absorbed more effectively than calcium carbonate—it’s about 30 percent absorbed. Calcium citrate malate is one of the most highly absorbable and expensive forms of calcium. Calcium citrate supplements are well absorbed, either with meals or on an empty stomach. You won’t find more than 300 milligrams of elemental calcium in calcium citrate pills.
• Calcium chelates (HVP chelate) are supplements that contain calcium bound to an amino acid. In the case of calcium HVP chelate, the amino acid is from vegetable protein. Some manufacturers claim that up to 75 percent of calcium in the chelate form is absorbed by the body.
• Effervescent calcium supplements contain calcium carbonate and often other forms of more absorbable calcium, so they may be better absorbed in some people. And because they get a head start on disintegrating, they may be absorbed in the intestinal tract more quickly. Dissolve these in water or orange juice.
• Calcium from bone meal or dolomite or oyster shell is not recommended, because some products have been found to contain trace quantities of contaminants such as lead and mercury.
2. Determine how much elemental calcium each pill gives you. Look on the list of ingredients for this information. The amount of elemental calcium is what you use to calculate your daily intake. Calcium carbonate or calcium chelates may not be 100 percent elemental calcium. The front label may state 500 milligrams, but when you look on the back or side of the bottle at the ingredient list you may find the product contains only 350 milligrams of elemental calcium. This will determine how many tablets you need to take to get your recommended dose.
3. Choose a formula with vitamin D and magnesium. These nutrients work in tandem with calcium to promote optimal bone health. For instance, vitamin D increases calcium absorption in your intestine by as much as 30 to 80 percent. As you will read later in this chapter, magnesium may also help ease certain PMS symptoms.
4. Spread larger doses throughout the day. Since all calcium sources, including food sources, are not 100 percent absorbed, it makes sense to split a higher dose over two or three meals. If you’ve been advised to take 600 milligrams of calcium a day, take a 300-milligram tablet with breakfast and another one at dinner.
5. Take your calcium supplements with a large glass of water.
The daily upper limit for calcium intake is 2500 milligrams from food and supplements. In most healthy people, this amount will not cause any side effects. The major risks from getting too much calcium include kidney stones, constipation and gas. In people who have a history of kidney stones, excessive intakes of calcium—greater than 2500 milligrams—can increase the risk of stone formation.