If you become tired and have difficulty focusing between meals, consider eating a snack to boost your energy levels. Granola bars and energy bars are small, portable snacks that give you fuel during the day. No clear criteria define the differences between granola bars and energy bars.

Keppra is one of the anti-seizure drugs that may be prescribed to the 2.3 million Americans who have epilepsy. Like many medications, Keppra can interact with other drugs and nutritional supplements and may cause deficiencies of the B-complex vitamins.

Biotin, sometimes referred to as vitamin H, is part of the B complex vitamin group. It is an essential vitamin that helps your body produce energy from the foods you eat. Calcium is an essential mineral that builds and maintains strong bones and teeth.

Vitamin D -- an essential nutrient found in dairy products, fatty fish and fortified cereals -- plays a role in your health. It helps maintain strong bones and teeth, supports nerve and muscle function and interacts with your parathyroid gland to help maintain your body's hormone balance.

Caffeine is a stimulant found in foods and beverages including coffee, tea, cola, energy drinks and chocolate. Some medications also contain caffeine. Although caffeine can give you energy and help you stay awake, it can cause side effects and may reduce the absorption of some vitamins and minerals.

Constipation is characterized by hard stools that are difficult to pass. Stool softeners and bulk-forming and stimulant laxatives help alleviate constipation in different ways. Lubricant laxatives, such as mineral oil, make it easier to pass a bowel movement.

Drug interactions are a serious matter that can lead to lasting health effects, so whenever you start a new medication, you have to double-check that nothing you’re already taking will create problems for you.

Chia seeds have been found to possess anti-cancer properties, with studies suggesting they may reduce the risk of breast and prostate cancer. However, it's essential to consult a doctor before using them as a natural treatment for cancer prevention.

Vitamin C is a water-soluble nutrient that your body uses to construct tissues like skin, hair and nails. The University of Maryland Medical Center explains that vitamin C may be effective in decreasing the risk of developing hypertension and certain types of cancer.

Calcium is the most abundant mineral in your body. Although the bones contain 99 percent of the calcium, the remaining 1 percent in the blood must remain within a very narrow concentration range to support vital physiological functions.

Vitamin C, or ascorbic acid, is a water-soluble vitamin that has several physiological effects on the body. Found naturally in citrus fruits, green vegetables and tomatoes, vitamin C helps form cartilage, bone and collagen. Vitamin C also has antioxidant properties, protecting cells from free radicals.

The amygdalae are small, bilateral regions in the brain considered part of the limbic system. As such, they are important in the processing and regulation of memory and emotions, especially fear and anxiety.